The The Flash followed and its main hero, Barry Allen, quickly became friends with Oliver.
They stood against their enemies together and were there for each other whenever one of them needed help or even advice. But the same can't be said for Barry and Diggle. Even though these two characters are on friendly , it'd be a stretch to call them friends. Here are 10 reasons why Diggle and Barry aren't real friends.
Barry Was Responsible For Flashpoint
In his effort to save his mom's life, Barry accidentally created the Flashpoint which led to the birth of a brand new reality. While some heroes were affected more significantly (such as Caitlin who became Killer Frost), even Diggle didn't get out of the Flashpoint unscathed.
Before the event, he had a baby Sara named in honor of the then dead Sara Lance. But when Barry messed with time, baby Sara changed into a boy John. Needless to say, when Diggle found out about it, he wasn't all that thrilled.
Life Outside Of Superheroism
Barry and Diggle mostly lead separate lives and they only meet when there's a crisis one hero can't deal with on his own and has to work with others. But they're not that interested in the other one's life outside of superheroism.
Diggle and Barry never hang out in a pub or anywhere else, as Barry does with his other friends, for example with Caitlin when they went and sang karaoke together.
They Don't Show Up
Neither of the Arrowverse heroes has an easy life, and Barry and Diggle are no exceptions. Barry lost both his parents and had to deal with the loss of his daughter Nora. Diggle, on the other hand, has lost many friends and also his brother Andy.
But when there's time to get emotional , they don't show up to give it to one another. Instead, Diggle talks to Oliver or Felicity or his wife, and Barry finds comfort in Joe, Caitlin, Iris, Cisco, or even Oliver.
Different Characters
Barry is mostly known for his optimism. While he has his dark moments, he does his best not to succumb to them. It helps that he's surrounded by a large group of people who love him and encourage him.
On the other hand, Diggle is much more restrained in expressing his emotions. While he's not as bad at this as Oliver, he and Barry are still too different in their approach to life to ever become genuine friends.
Barry Became A Villain
There's another reason why Diggle might not be so keen to be friends with Barry - and that's the fact Barry can't be entirely trusted. He sometimes does more harm than good, even though he doesn't plan to, and he lets his emotions cloud his judgment.
But what's more, Barry has the potential to become a villain, as the fans saw when it was revealed that the evil Savitar was actually Barry from the future. Diggle, on the other hand, remains on the side of good, even though he also sometimes doubts himself.
Barry Is Smarter Than Diggle
Barry makes many mistakes in his effort to save his mom and help other people, so it's sometimes easy to forget that even before he became the Flash, he was already a super-intelligent CSI assistant and something of a miraculous child.
Diggle, on the other hand, while he certainly isn't stupid and he can come up with a strategy on how to defeat his enemy in direct combat, is nowhere as smart as Barry and he often struggles with understanding scientific concepts and ideas that Barry has no problem with.
One Has Powers, The Other Doesn't
There's always an imbalance between a super-powered and non-powered hero in superhero shows and movies, no matter how strong or clever they might be. The tension is visible even between Barry and Oliver when Barry accuses Oliver that he's jealous of his powers.
And Oliver is even much better trained at fighting than Diggle who can't, for example, shoot arrows as well as Oliver, and isn't as proficient at hand-to-hand combat. Having superpowers changes you and that's something Diggle could never really understand about Barry and his life.
Barry Went Against A.R.G.U.S.
Diggle doesn't have that many close people, but he's very loyal to those he loves, and his wife Lyla is the most important person in the world for him.
While Barry never hurt Lyla in person, he sometimes went against A.R.G.U.S., the secret agency Lyla leads in order to fulfill his plan. And if that meant stealing from A.R.G.U.S., Barry was game. That's not something one should do the wife of his friend, and it's yet another reason why Barry and Diggle aren't real friends.
Diggle Doesn't Like Metahumans
It's difficult to overlook that most people Diggle works with closely are normal, non-powered people, even though they're often well-trained and intelligent. That's because Diggle doesn't like metahumans that much. He's somewhat old-fashioned in his views and has a hard time imagining people with superpowers really exist.
He doesn't react positively at first when he's confronted with the fact that Barry is super fast, and even though he later grows somewhat accustomed to it, he'll never fully accept Barry's powers.
Barry Spends More Time With Oliver (And So Does Diggle)
Finally, the main reason why Barry and Diggle aren't real friends is that it's Oliver who's Barry's friend. These two didn't always see eye to eye but they eventually grew closer when Barry first saved Oliver's life and then teamed up with him on multiple occasions and trained with him.
When Oliver died, Barry grieved him, even more so when he realized Oliver sacrificed his life for him and Kara. Theirs was a deep bond and such a bond never existed between Barry and Diggle.