In many (or even most?) companies where I live and work, it is not that bad. My boss will not try to interact with me past 5pm. If we have a meeting just before 5pm, he will wish me a nice evening. I would not have taken the job otherwise -- yes, probably that cost me some salary.

I have refused to be contactable outside of work hours everywhere I have ever worked. It works great: as long as you never allow an expectation to be made that you will be reachable outside of business hours, most workplaces will cope.

My boss has a life too, why would he want to interact with me outside business hours?

outside of happy hours or whatever social thing we've both chosen to be at

I'm in upper management, I'm salaried, and I did just that when I was hired two years ago. My boss said, "Great!". I told him I have notifications for GMail disabled 24/7, and that Slack only notifies me during work hours, M-F. He said, "Wonderful!". I'll take three days off mid-week to go camping in the backcountry and will tell him I'll be entirely out of service. He'll say, "Good for you!" in a genuine way.

It's literally never been a problem. I'll come in to the office, respond to messages received afterhours and nobody cares that it took me until my shift to get back to them.

I know plenty of other people who also don't have that pressure. Careful with your snark next time.

Probably depends on one's role in the org. As an IC I've never had this be a problem.

My boss would give me a thumbs-up. Perhaps you should consider other teams or workplaces?