They don't call him Amazing for nothing!
Spider-Man may be the youngest of the Avengers, but nobody on that team has more heart than he does. Peter Parker has longed to be a member of the super-group since he first helped Tony Stark in Captain America: Civil War and that moment finally came when he joined them in space and fought Thanos on Titan.
Spider-Man's abilities speak for themselves. He's easily the most mainstream name on this list and one of the best-known superheroes in the world. If you know of Spidey, you know he has the incredible ability to swing from buildings on artificial webbing, to climb those same buildings like an actual spider, and to sense danger before it happens.
The MCU iteration also has enhanced strength and durability which makes him very formidable in the field - even against more powerful opponents (remember how he was able to prevent an attack from The Winter Soldier by simply holding his arm?). And let's not forget how formidable he was in the many variations of his Spider-Man suit designed by Tony Stark. From the Instant Kill mode in Avengers: Endgame to Karen's state-of-the-art combat modes, the MCU's Spider-Man had it all.
He may not be an Avenger anymore (for now), and there may be more not-so-friendly neighbourhoods in his future, but with more growth and maturity, Spidey could return as the greatest hero the MCU has ever seen.