That’s kinda the point I’m making, though. Up until Infinity War, the Avengers were a terrestrial superhero team. The biggest threat they had faced as a team was a genocidal murderbot of their own design and, honestly, Thor was punching well below his weight in that regard. In his own movies he was fighting literal gods, so Ultron and HYDRA and regular ol’ arms dealers were never really on his level. Even in 2012, during the Battle of New York, the aliens they fought were pretty lame and the universe at large didn’t think much of it.
Fast forward to 2018, however, and the Avengers are fighting Thanos, one of the worst people in the entire universe that has killed half the population of many worlds across the universe and, after gathering the Infinity Gems, successfully kills half of all life in the universe. Five years later, those same Avengers bring everyone back. At that point the Avengers are no longer merely a terrestrial team and Earth is no longer just some backwater world nobody wants to visit, half the universe literally owes the Avengers their lives. If that doesn’t promote the Avengers to superheroes of the universe who travel across galaxies to fight bad guys, nothing will.
You’d be right if Carol Danvers joined the team in, say, Age of Ultron like the behind-the-scenes stuff says she was originally going to, but post-Endgame I can’t think of anyone better than Captain Marvel to lead a new Avengers team that fights threats across the universe like Galactus or errant Celestials threatening to judge civilisations to determine if they’re worthy of their continued existence. Heck, could you imagine the Shi’ar Empire showing up on Earth one day because this primordial creature known as the Phoenix just destroyed their home world and chose a human from Earth to be its host and Captain Marvel is like “If you think I’m letting you invade Earth you’re pretty stupid” and then she gets into an epic fight with Gladiator?