@wessexweather
I've used UBports UbuntuTouch on several different phones, and it's my daily driver. Currently on a OnePlus Nord N100: very cheap on eBay. For apps that aren't available for UTouch, I also run a selection of non-Google Play Android apps (from f-droid and apk downloads) in a Waydroid container, using the Waydroid Helper tool from the UbuntuTouch OpenStore. Even in Waydroid, my bank's app won't work on it, because it's a rooted device, so instead I just use a browser. It seems not possible to use UTouch for making payments, as you could with Google or Apple. The UBports installer is really great, but required downgrading the handset to Android 10, which required using a Windows-only download from Qualcomm, so access to a Windows machine is also needed. Once it's installed and running, though, #ubuntuTouch is super.

No experience with SailfishOS to compare it with. But if you didn't want the hassle of DIY flashing, you could buy a Jolla phone with Sailfish pre-installed.