Nothing, at all.
Some things you can’t do easily in Mint, like create snapshots automatically and boot into them when something breaks.
But it’s all Linux and freely available software under the hood, and the lines between configuration, customization and forking your distro are blurry.
Call your bank and ask them how to access your account without an Apple or Android phone.
Claim you need it for accessibility reasons.
Forcing you to use the product of one out of 2 tech corporations just to survive (for which you need a bank account) is ridiculous.