Perhaps Kagi would work for you? https://help.kagi.com/kagi/features/website-info-personalized-results.html

You can generally add "-" before a domainname for search engines to prevent content from that domain showing up.

So for reddit, you'd search "weather -reddit.com". It should work. This is short and generally works but If it still shows up "weather -site:reddit.com".

you can also add multiple domains like "-reddit.com -stackoverflowclone.com -seojacked.com"

You can also do this by default using custom search engine with a search string that already contains the domains you don't want.

For ddg:

https://start.duckduckgo.com/?q=%s+-reddit.com

Yes please. Pinterest should be entirely filtered out of all search.

Maybe https://iorate.github.io/ublacklist/docs

uBlacklist

The search sytanx is like this if you want to have results without facebook face -facebook https://search.brave.com/search?q=face%20-facebook Maybe you can add %20-facebook to the search engine as default.

This is very easy to do if you use kagi. It works well on Firefox for android.