Everyone romanticizes this scene as sweet domestic bliss, but it’s quietly the most tragic setup in the movie.
Tony was the only Avenger who actually found peace during the Blip, he built a family, survived his trauma, and got out clean. Cap, Nat, and Scott showing up at his porch wasn’t just asking for help, it was essentially asking a retired man to put his offspring's and his own life on the line to fix a catastrophe caused by the team failing to listen to him years prior. He gave up everything so everyone else could get their lives back.