I've increasingly heard of places requiring that you put it on your personal phone for working class jobs. BYOD gone horribly wrong. The same app will also be the only way to get your timesheets, clock in, or trade shifts, etc.
BYOD has indeed been a curse.
If the app did give the employees the tools to separate their lives, the employer would churn to another app.
In fact, skilled advertisers and psychologists and the kind of people who develop dark patterns for social media companies[1] likely have more control over it than you have.
[1] and your company’s glorious loyalty oath parade, logos on mugs on your desk, anti-union propaganda posters, slogan you recite on the phone, etc. It is all changing you one way or another.