Yeah, this. I assume the OP is talking about store brands, since I haven’t seen many true generics in a long time.
For the most part, the store brands I’ve tried have been acceptable alternatives. Either I can’t tell the difference, or they’re noticeably different in a way that’s close enough to “alternative brand” as opposed to “cheap knockoff.” But then again, nowadays it’s hard to find groceries, even store brands, that are truly cheap.