Security of Frontends (and of safe browsing more generally)

I would like to use Frontends such as Invidious, Teddit, Tubo and espiecially the extension Libredirect which automatically connects to Frontends. But I am deterred by the lack of information on how trustworthy these are.

The way in which there are dozens of different “instances” reminds me of movie piracy sites which I always believed would somehow damage my system with malware or make me easy to hack. I don’t know how rational this concern is, as I don’t have the knowledge to know what the risks of using websites of the sort could possibly be.

I am using these Frontends via Browser instead of download for the same reason of exercising caution with things I do not understand. But I read somewhere (this website I was convinced, but could not find since), that downloading applications is better than browsing for security/privacy - but it seems like downloading things is the last thing an ignorant web user should be doing.

I see, I guess my concern would be that an instance uses software which is not identical to the other instances, but has something malicious sneaked into it.

By cross scripting, are you referring to frontends in general, or the re-directs in general. If frontends in general, I don’t understand how content posting on say Youtube or Reddit could be used to exploit. But maybe I’m misunderstanding what you mean by “frontends could be exploited by content posted”?