Therefore, by adding multiple ways to log in/recover an account, each additional one lowers the safety?

Also, worse: does this mean that by just having one bad 2FA/recovery method like SMS along with more secure ones like TOTP/RFC 6238 or hardware keys, the overall security level is as low/bad as the worst method undermining the rest? Why do companies still allow or even encourage multiple methods (and SMS)?

I love the convenience of SMS sometimes, but if it doesn't add any security at all, just a sense of fake security that they won't even need an IMEI from me, just my phone number, jeez. This should be solved or forbidden by major institutions and services.