Thank you for rising awareness.
Imho it's not that difficult to set password manager browser extensions for mitigating this, just then it will impact (heavily) user-friendliness.
Clearly the two options are:
* (best) give up password managers and use pen-and-paper (not simpler passwords! no password reuse!)
* (imho not too bad) unlock password manager separately (maybe in a browser used *only* for this job, not for browsing), keep it locked as much as possible

Of course, keeping seed or private key in a password manager is imho insanely dangerous.