PiHole unfortunately doesn’t work against YouTube ads - at least it never worked for me. It’s good for everything else tho. You would have to use ublock origin on desktop and an alternative YouTube client (like newpipe or grayjay) on mobile

Not having access to your phone and having to log in on other computers doesn’t rule out using password managers at all. You can use bitwarden’s web vault (or self-host vaultwarden). As long as you can log in to bitwarden web vault, you can access your passwords anytime, anywhere.