I thought this was a limitation on the carrier you used, rather than the brand of phone? While I’ve not used any Samsung phones (well, none that ran Android), I’ve gone through various carriers and some of them have supported VVM in the Google Phone app, and others don’t seem to.
That’s quite unfortunate to hear. I use Bitwarden along with Gboard and very rarely run into issues - I believe most password managers have a quick settings toggle that you can add into your notification drawer to maybe get around this? From what I know though, these generally use the Accessibility framework to function, and thus will heavily depend on your password manager - it also gives a lot more access to those apps than the built in autofill framework.
Conversely I remember Bitwarden’s autofill support on iOS being quirky when I last used it (which to be fair, has been a while - I’m sure its improved since then). IIRC it pretty much always worked in Safari (and Safari Web Views within apps), but the actual applications themselves wouldn’t always give me the autofill prompt.
For me though, regardless of the platform it still is far more worth using a password manager and unique passwords per-site than to use a single password (or even a handful) across sites. I hope autofill support improves for those that it doesn’t work well with.