The The Big Bang Theory. Despite primarily being an origin story to Jim Parsons' fan-favorite character on the nerd-centric sitcom, Young Sheldon has actually evolved past its initial premise. Now, it has become a family comedy that puts more focus on the rest of the Cooper clan. This has broadened Young Sheldon's appeal beyond fans of The Big Bang Theory. However, this has also made it increasingly clear that all Cooper family have grown up to be the worst versions of themselves.
While Young Sheldon breaks away from TBBT, both shows officially still exist in the same reality. This is despite the numerous plot holes between them. Arguably their biggest narrative inconsistency is the depiction of George Cooper. Based on Sheldon and Mary's stories in The Big Bang Theory, he was a no-good, negligent father who always drank — something that Young Sheldon has continuously seemed to debunk. However, the Cooper patriarch isn't the only member of Sheldon's family who is worse on the nerd-centric sitcom.
5 George Cooper
Sheldon had a penchant for sharing stories about his childhood in Texas, which was the original inspiration for CBS greenlighting Young Sheldon. He talked about a mix of things — from his experience being bullied to his early scientific endeavors. However, one of his most interesting anecdotes were about his dad. So while George isn't one of the Young Sheldon characters who appeared on TBBT, his character was already established as a bad father when the prequel started. However, that is simply not the case in the prequel series. While George has his shortcomings, he has been committed to his family, especially in of providing for them.
4 Sheldon Cooper
Despite The Big Bang Theory starting as an ensemble series, its storytelling eventually shifted, putting more focus on Sheldon and his personal arc. Thanks to his friends' relentless and guidance, however, what was once a snooty and highly insensitive person became better, albeit gradually. Interestingly, however, the socially-inept genius isn't nearly as rude or dismissive in Young Sheldon. In fact, aside from the fact that he can be dense and emotionally stunted, he is quite reasonable — far from the tantrum-throwing man-child in the flagship sitcom. Suffice it to say, TBBT's Sheldon is worse than Young Sheldon's.
The CBS family comedy featuring a nicer Sheldon has resulted in other tangential plot issues. For starters, The Big Bang Theory always emphasized the Pasadena gang being Sheldon's first social group. Because of his underdeveloped social skills, not to mention his overall difficult personality, there was an idea that he never had any friends growing up until Leonard and the rest started hanging out with him. As revealed in Young Sheldon, however, that isn't the case, as Sheldon has long been perfectly capable of making human connections. He had friends at Medford High School and at East Texas Tech, suggesting he lied about his childhood experiences in TBBT.
3 Mary Cooper
Aside from Sheldon, Mary Cooper had the most appearances on The Big Bang Theory. She often visited Pasadena to check up on her son, but in other instances, the socially-inept genius went back to Texas to see her. Because of this, Mary's sad fate after Young Sheldon has already been revealed. While the Cooper matriarch retained some of her signature qualities, it seemed like The Big Bang Theory amplified his negative traits. The nerd-centric sitcom featured a highly-judgmental devout Christian who could be rude, sexist, racist, and misogynistic.
What makes this worse is the fact that Sheldon's friends were often the target of her tirades, not realizing how important they are to her son's well-being. She was unnecessarily mean to Penny because of her romantic choices, Raj for being Indian, and Howard for being Jewish - all of which was entirely uncalled for. Although Young Sheldon's Mary has the tendency to be overbearing, she isn't nearly as callous and rude as her The Big Bang Theory counterpart.
2 Missy Cooper
Although Missy barely appeared on The Big Bang Theory, she immediately resonated with audiences as Sheldon's twin sister. As Young Sheldon delves into her story, the CBS family comedy is benefiting from the character's initial impact, as she's one of the most popular characters on the show. Despite not being intellectually gifted like Sheldon, Missy has proven time and time again that she is the best Cooper, as not only is she charming and witty, but she's also fiercely loyal and emotionally mature for her age. She provided for most of her family as they deal with their respective issues in Young Sheldon season 5.
Sadly, despite her childhood potential, The Big Bang Theory painted a bleak future for her. Not only does Missy become the least successful Cooper sibling professionally, but she was also stuck in a horrible marriage for a significant period of time. Sheldon, despite all his character flaws, ends up surrounded by a great system and happily married, not to mention a Nobel Prize winner. Meanwhile, although Georgie has a tumultuous romantic life, with several divorces under his belt, he becomes a successful businessman, owning the most popular tire chain in Texas.
1 Georgie Cooper
Georgie has also followed this trend, having become the center of Young Sheldon's storytelling ever since the show introduced his and Mandy's unexpected pregnancy arc in season 5. For the most part, the prequel has done a good job backing up the flagship sitcom's depiction of the character, especially in of setting up Georgie's TBBT grudge against Sheldon, not to mention his eventual success as a business owner in Texas. However, like the rest of his family, Georgie also appears to be worse by the point audiences meet him in The Big Bang Theory.
While George doesn't necessarily share Sheldon's intellect, he is patient, responsible, and arguably the sweetest out of the Cooper kids. However, he came off as cocky, and even a bit of a playboy on The Big Bang Theory. So, despite being committed to making things work with Mandy - especially as the birth of their baby nears - Young Sheldon doesn't have any choice but to split them up to preserve the established continuity. This effectively ruins a great narrative in the prequel that could have resulted in the Coopers expanding their clan.
Young Sheldon season 6 airs Thursdays on CBS.