The issue I've always taken to this sort of introvert/NEET/bum-given-a-second-chance sorta thing is that their past experiences are always so incredibly wack. And I understand this may be because despite having my introverted times, I was never really ostracized and bullied like these characters, but it does make these series less relatable to me when the "trauma" they overcome is people being comedically evil and disproportionately mean for no reason.
That said, I still enjoy the self improvement narrative that many of this sort do promote. Unless it comes with a harem and on-the-nose fanservice with very little actual character change from the protagonist except a physical makeover. In which case the author has missed the mark completely and is probably just bitter that they aren't as attractive in real life as their social power fantasy protagonist and whoever the hell they saw as the social butterfly in their formative years.
Tldr; I'm a bum, I like reading about bums, but don't make the bum's story too wack or too full of bums or I'll be bummed out.