The way I see it, people who are careless with security have put people who are technically able to deal with things like client-side TLS certificates in a compromised position where they have to deal with SMS or email based MFA for important services like their bank, credit cards, taxes, etc.

I would rather have the ability to use real security with the MFA scheme I described above (and in my other post [1]) rather than the security theater we have with email/SMS MFA. If some people aren't able to deal with that and lose access to their account, then the burden is on them. On the other hand, by using email/SMS based MFA and account recovery, the burden is on all of us for the lack of security for everyone. If someone wanted to get into the important accounts, they don't necessarily need to target the user's bank. They could target their cell phone provider or email provider and get access not only to their bank account, but any account using those as factors for authentication.

With a client side TLS certificate, they would actually have to get physical access to the device and brute-force the private key passphrase in addition to the username and password for the account.

[1] https://news.ycombinator.com/item?id=23583676