It is technically possible to install paru through Cargo which you can get just from pacman by installing rust and you can install pikaur through PIP. Both can mess with your systems packages though so I do not recommend it.
These are great suggestions, but for finding communities, I would recommend https://lemmyverse.net/communities instead.
The Interface is nicer, you can directly get the !community@instance.tld string for searching it locally, and it doesn’t use a large blocklist like feddit.de sadly does.
And even with that subscription, you still get locked out of any post or subreddit that is marked NSFW, which will now be even more since subreddits are still protesting the changes.
Good Bot!