A company cannot force you to use your hardware to run their business at least not without compensation. Having a phone number that can be paged is significantly different than installing MDM software that can track literally everywhere you go, wipe your phone without your permission, etc. If a company is saying you "must" install something in your personal device without any compensation on top of your regular paycheck this is incorrect. If you use your own car for work you're typically compensated with mileage or you can write it off on your taxes.