That’s very true and also not recommended. You’re supposed to sand before you paint. ;-)
Back to BIN, which I cannot possibly sing loudly enough my praise of it. It sands like a dream. So if your surface is properly sanded primed and smooth and free of debris and dust, and you still feel the need to sand the paint, then you’re doing something wrong, in my humble opinion. Whenever at all possible I use a roller to paint with because the finish is more even and anyway it’s faster. So if you’re sanding brush marks, try a roller. If you’re sanding debris out of the paint, don’t. Use a scraper (painter tool, not a razor blade) and knock the debris off, then go buy a higher quality roller and touch it up.
Good paint makes a difference too. There is more “paint” in good paint. And for a few projects around the house, the price difference is so small that the headaches are not worth the savings. I could paint all the doors in my house with less than half a gallon. Don’t cheap out with paint. It’s just not worth it.
One more painting tip. If you’re like me, and not a professional painter going through gallons a day, and you need to store the paint for long times between small paint projects, use a plastic cup to scoop the paint out of the can instead of pouring it from the can. Keep the rim clean and the can will seal every time you close it and you won’t be tossing spoiled half full cans. Obviously I’m talking about small woodworking projects, not painting a room.
Losing fingers since 1969