1password for unique long passwords per account. I store OTP in 1password as well for the extreme convenience it offers on desktop & mobile.
Backup TOTP are put in .txt files for each service and in a folder encrypted by Cryptomator (using a unique pw not used by any other services, esp. 1password). This encrypted folder is put on flash drive on my keychain and synced into my google drive folder.
This feels to me like a pretty good balance between convenience and security. Not 100% of my eggs are in one basket, but it's true that my 1password account password needs to be long and well-guarded and never re-used for anything else. Also putting a lot of trust into 1password to not get breached...