2FA isn't limited to one device, or specific 2FA mobile apps. For example I use oathtool for most 2FA things; you just need to store the secret (often in the form of a QR code, but many services will also offer a text version, and if not you can decode the QR).

100% reliance on a phone which is easily lost, broken, stolen, etc. without backup is really bad IMO. My bank (Revolut) only had a mobile app, and no way to contact them outside of it (I tried...) I need to switch banks.

Revolut now has a web app [1], which still tries to get you to log in via the mobile app but this is not necessary. So long as you know your pass code and have alternative access to your email then you can log in and do most of the things you can do via the app. You do have to wait 10 seconds for the privilege though (before allowing access via email there is a timer before you can confirm you do not have access to the mobile app.).

1. https://blog.revolut.com/introducing-the-revolut-web-app/

The web app doesn't allow basic things like transferring money. It's borderline useless.

This is becoming the standard now. Can only contact certain corporations through their mobile app, not through their web site (even if logged in).

This utility will help with that, assuming the services that use 2FA have a backup-code feature: https://github.com/sowbug/quaid

That sounds like a bad planning problem in which you shouldn't have left yourself vulnerable to loss of electronic services. Not a tech issue that justifies intrusive spyware.