It can be, but doesn't have to be. "High performance" is just too vague to try and draw inferences about individual companies.

I work somewhere with what I would consider a high performance culture. We all show up to work and consistently put in ~8 hours of high effort work. A few times a year that may mean some late nights, but mostly not, and folks usually take 4-8 weeks of vacation a year. Working around the clock is not rewarded. I find the whole setup fun and invigorating.

That said we do sometimes make a bad hiring decision and those people may end up working 80 hours a week to try to match the output everyone else. We have to let those people go.