For me, I can't switch to Linux because of my accounting software; it's only on macOS. They are very few Linux business accounting software programs suitable for sole proprietors. GNUcash is too hard to set up. Online accounting software is not good, because one is giving ownership of one's financial data to another entity, who could deny access at any moment.

I've had five clients who have lost access to their Microsoft accounts permanently due to insufficient, or old, recovery information. SMS can't be used anymore. I've been thinking about recommending Yubikeys, but when older people don't even want to use password managers because they don't trust them, that's a hard sell.

The biggest problem is Microsoft changes the rules and requires all of these features, but doesn't tell any normal users of the changes nor the addition of the features.

Namely, it's the "blockers" one hasn't found suitable replacements for.