My brother was in this situation many moons ago. He went to our large, state flagship and while he didn’t fail out, he didn’t meet my parents’ (reasonable) expectations. I was away at school at the same time, so I don’t know what the mix was of issues in terms of mental health/depression (which he has continued to face)/general maturity/homesickness/being overwhelmed academically/etc., really was. But he came home for a year and was enrolled in the local branch of the state flagship. He did fine, regained my parents’ confidence, and return to the main campus for his junior and senior years. He did change from an engineering major to a humanities major, but he was probably ill-suited for the engineering major regardless. He graduated on time and has led a responsible and productive adulthood.
I hope your son’s story is similar. Not everyone is ready to go away to college at 18. My brother wasn’t and I think a lot more kids than normal weren’t this year because of the trauma from the pandemic. But it doesn’t mean that they won’t be ready at some point, or won’t be able to carve a great path for themselves.