What are your thoughts on bathroom breaks? As far as how many and for how long before it becomes an issue?

I see coworkers abuse the hell out of it, leaving more work for myself and others when they’re gone. People here always defend bathroom use, I get it, but how much is too much before there’s a problem? Surely someone can’t spend 50% of their shift in the bathroom? I know some of my clown coworkers are on their phone while they’re in there lol