My YouTube use definitely isn't healthy, but it's still the only social app that asks me to take a break if I use it too long or late at night. That should be standard in any of these apps.
Does it recommend taking a break? Mostly I've seen it ask if I'm still watching. I've always assumed this is not for user benefit, but in order to not spend bandwidth on a screen that is not being looked at.
The only site I'm familiar with that has somewhat decent self-limiting functions built in is HN's no procrastination settings. But that's of course because HN isn't run to make money, but as a hobby.
Youtube isn't doing that for your health. It's so they're not wasting ads and bandwidth on users who aren't watching anymore to maximize their profits. The sole purpose of a for-profit corporation is to generate revenue for its owners and shareholders. That's it. Nothing more, nothing less. Do not expect anything different. Corporations only care so long as its profitable.