MCU Phase 4 has highlighted how important Captain America is but, more than just the Star-Spangled Man with a Plan, the MCU needs the Avengers team considering the contemporary circumstances. Marvel Studios is moving on from the Infinity Saga to MCU Phase 4 with Disney+ shows that focus on character team-ups. At this point, there's no word on when Earth's Mightiest Heroes will re-assemble in the franchise, but the state of the world following Thanos' defeat is calling them to reconvene sooner than later.
As the MCU goes through this transition phase, it makes sense that Marvel Studios is prioritizing standalone stories rather than jumping immediately to doing another event offering. For starters, the Russo Brothers delivered. Second, the franchise needs to build itself back up after the demise of several founding heroes, including Iron Man, Captain America, and Black Widow. That said, given what's revealed about the post-Infinity Saga world thus far, the MCU could really use their most prominent roster of heroes to help re-establish global order.
Steve Rogers and the legacy of his Captain America was at the core of time heist in Endgame (to return the world to normal). However, considering how precarious things are, Captain America alone isn't enough to do the trick. Instead, it's the original Avengers team that needs to return. Steve's absence may not be this greatly felt if the rest of the team is still visible and operating. While only half of them are out of the franchise, they're technically inactive as a team. Thor is off-world minding his own arc; Hawkeye went rogue and may want to retire after helping Kate Bishop; and Smart Hulk is semi-retired.
The founding of The Avengers are viewed as a beacon of hope; they're the heroes who have repeatedly saved the world together and separately since they fought off Loki's Chitauri invasion in global politics in the MCU knowing that Earth's Mightiest Heroes are still in operation. But, more than that, they're also needed to properly help in the formation of the next generation of Avengers. As seen in both WandaVision and The Falcon and the Winter Soldier, most of their contemporaries are scattered, dealing with their own issues and in no form to take on heroic responsibility. With the original Avengers' guidance, it would be a much easier transition. Additionally, it could also help the public get more used to this new band of heroes.
Seeing the original Avengers intact at this juncture in MCU's history would be better for the franchise as a whole. Unfortunately, that's not how it's going to be. If anything the god-like status of them – even those who aren't actually gods – makes it more difficult for new heroes. To take their elevated positions, they have to deal with the legacy of those who precede them, as depicted with Sam replacing Rogers as Captain America. That said, this Avengers line-up can be better as it will have hopefully learned from the mistakes committed by their predecessors.
