I have similar requirements to you and honestly the best solution I could find was Microsoft Authenticator. I know Microsoft bad etc, but if you already have a Microsoft account anyway you can back up all your 2fa codes to your iCloud or Google account. If anyone knows of an open source alternative I’d be interested, but the ability to recover my accounts is more important than using something open source
Honestly looking at the article this seems way less intrusive than pre-roll and mid-roll video ads. If this was to replace them I’d be ok with that. But this is Google so of course it’s just going to be as well as, so my adblocker is staying on for as long as it works