Why would you have one device for work and another for private life? I use dual SIMs on my work phone. I used to use two phones but that was just very, very, very inconvenient.
Why try to cram in two lifes into the one life you have?
I don't want to have anything personal on a device someone else has full control over.
I don't want any work-related notifications after I clock out. If I'm being paid to work 8h/day, company has my attention for 8h/day. Overtimes can be arranged, but doing so on my own will and not being paid for it will never happen.
I don't want to be held liable for leaking company secrets in case I lose my personal device.
"I don't want to have anything personal on a device someone else has full control over."
You don't want a smartphone then. From the ground up these things are closed source with smatterings of OSS in highly visible places which can be negated utterly by lower level software.
At some point we all have to realise that anything we posess electronically is only a copy of the version the three letter guys have in our files.
If the choice is between sharing my data with a three letter agency thousands of kilometres away and sharing my data with a three letter agency and my employer, you're damn right I'm choosing the former.
I even refused an otherwise sensible request from my former employer to install WhatsApp on my phone because I was not interested in using it personally, and they were not interested in providing me a work phone for it.
Why try to cram in two lifes into the one life you have?