There's just one problem: increasingly, everything that makes a phone a "daily driver" is the thing that can only work on the "important" phone. Banking/finance, government services, commerce, work, communications (thanks a lot E2EE), and DRM-ed entertainment - all the major players here are locking their software down and relying on remote attestation to ensure their locks stay shut.
With this being the trend, you're already more likely to leave what you called "daily driver" phone home, and only take the "important" one with you.
Still waiting for someone to make a tiny token sized phone. Unfortunately the smallest around, Unihertz Atom, is both outdated and too low resolution for some apps to work.