I do think it depends on the particular fish but a bit less decor has worked for some. Many fish tail bite because their fins are a heavy nuisance to them, and often long heavy finned males do better in smaller tanks, and less decor means less they have to navigate through and around while they're hauling all that weight.
But some tail biters seem to do better with more or less decor, being able to see another Betta or not, bigger or smaller tanks, more or less stimulation. Finding the cause or the perfect combination isn't usually easy. VitaChem is beneficial to all fish because it boosts the immune system (similar to IAL) but it will also help with damaged fins (along with stress coat). Some tail biters will tail bite no matter what. Others go through phases (like, as soon as their tail is almost completely grown back they chop it off again, lol).
Its an issue and it ruins their pretty finnage but I see it as a personality trait. I personally think that "picky" tail biters are stubborn and full of personality. They're harder to please but that just make the relationship between the fish and the owner stronger (like an annoying younger sibling
). Sometimes tail biting cannot be cured but VitaChem (and stress coat and Indian Almond Leaves) will help keep them from getting infected, though its no replacement for clean water.
I've never had a tail biter but many of my friends on this forum have (I love hearing stories, lol) and I always use VitaChem. Plus, I have a blind male so I think I've had my fair share of "special" fish.