If companies also perceive that Android is a serious threat to their security, then let them issue iPhones / Blackberries to their staff. I have never known a company that actually expected their staff to provide a mobile phone, it was always a company asset and had to be handed back upon leaving their employment and strictly NO private calls were allowed.
Blackberry is dead.
in Sweden, people provide or get issued phones, depending on work. I've had an issued phone the last 26 or so years, and the restrictions on private calls have initially been different. My stance was, that either $EMPLOYER swallows the bill, no questions asked, or I turn the phone off when I leave work for the day. It's worked out well. Employer did not make a fuss.
With the phone being very much a infocentre for your complete life (and that's something you can't avoid, period.), the question is if you want your employer to own your phone. I chose to split work and private phones simply because of this. And I'm very much conscious what apps and which data that go on which phone, just because.
Today, one gets free minutes and SMS, in the entire EU, and a sensible blob of data. I get 25GiB a month on my private phone. Never run out. My work phone gets unlimited data in Sweden and something like 100GiB in the EU. And free calls/SMS.
The US market of course is shat, and the UK will be too, but that's something you can thank the über-twit Rees-Mogg for.
Bottom line, you get a working phone or you lose. It's not nice, but that's where it is. We chose to give our children second-hand iPhones that have been professionally refurbished, and that keeps cost at a reasonable level.
For computers, the curve isn't as steep. At least if you buy a sensible computer. My laptop is very old; a "Early 2015" 13" Retina MBP. It still runs a supported OS, and it works for my needs; but the battery is near-toast and the storage is full. Both can and will be dealt with this autumn. The work computer of course is newer, a 16" Intel MBP with large storage and barely a year old. Those muscles are needed for "Bad web sites turned into apps" like Teams and others.