I agree, I think not only does the scene fit the rest of the film, but it fits the origin and his character, too.
If something tragic happens that you feel guilt over - say the death of someone close - this is the sort of conversations you have about it to strangers. You wouldn’t go into detail. Acting like you aren’t hurting inside is basic human behavior but Peter is obviously still struggling. If you look at him in both movies, he only becomes the joking and fun loving Spidey when he is alone or the mask is on, the rest of the time he has the weight of the world on his shoulders and is afraid to stand out (bar a few moments, mainly with Ned, and even then he’s not full on Spidey).
This is part of the reason I’ve said a second watch made me love Homecoming so much more. They completely nailed Peter as a boy struggling with a traumatic life change and a sense of responsibility through guilt. Spider-Man is his safe place, one where he can control bad things that may happen or face his fears. Then, each facet of his life begins to affect his actions in the other - when he has the suit taken away he finds the bravery in himself to tell a girl he likes her. Then, when he wills himself to rise through the concrete he literally says “Come on, Peter. Come on, Spider-Man, Come on, Spider-Man.”