Neither do I - I use either my phone, or my smart TV, or my fire stick. SSO works fine there, or you can use the QR based session transfer to SSO on your phone and then "sign in on another device" or whatever by scanning the QR your other device is showing. I think they call it quick connect or something.
It does what you want.
And if you think Grandma can't figure out scanning a QR code, Grandma is also not gonna figure out MFA lol.