[jrm4]

Exactly.

Now, why are they doing it for free? Why take on a huge responsibility for no money, what do they get out of it?

[Scion9066]

If people use this instead of passwords, they get less compromised accounts on their services that they have to deal with.

[ThatPlayer]

Less customer support for dealing with hacked accounts. Same reason places support and even push 2FA, otherwise what is their incentive to support 2FA?

Fortnite even has a free dance that you can only get by enabling 2FA.