I'm surprised they haven't gained wider adoption, their competitors charge yearly fees for their tokens, and in many cases you become dependent on their infrast

I'm surprised they haven't gained wider adoption, their competitors charge yearly fees for their tokens, and in many cases you become dependent on their infrastructure to use them. U2F is a one time investment as long as the token isn't damaged, and your not beholden to Yubico in the slightest. I've got a box of RSA tokens from former jobs. E*Trade still gives out some token with a LCD display for $20 a year as their sole 2nd factor option.