I keep banking apps off my phone and run them only on an iPad that never leaves home. It's a little clumsier for scanning checks. No biggie.
Of course, the phone has Apple Pay and keychain access ...
The "benefit" of Apple Pay is that by regular use, I am constantly reminded where the phone is. The watch hasn't griped about leaving the phone home when I take a spin around the "estate" here, so I'll check on that today. Matter of fact, neither does the phone when I drive off, leaving the other Apple goodies home.
More settings to check.