It's not really a rabbithole in most cases - unless you have exceptional expertise (and you'd know), you should trust someone else right away, not eventually, because you should trust yourself even less.

Even if you have good reason to believe that all available third party systems are vulnerable to one or another intelligence agency, using that would still be more secure than doing everything yourself, which you can't do properly (noone can do that without extensive review from a large community, so you definitely can't as well), and thus making a system that's vulnerable to everyone.