It’s based on Firefox, but those modifications do have a rather large impact in terms of privacy.

$ fuck

Comes in handy quite frequently.

That depends a bit on the ruleset. According to Guinness (where hyperventilating with pure oxygen beforehand is allowed), it’s 24:37.36. According to the freediving organisation AIDA (where pre-breathing oxygen isn’t allowed), it’s 11:35

Telegram being next to Signal is also questionable.

As someone who started out with Manjaro and used it for a bit over two years, it does its job alright. That said, Manjaro’s “let’s use Arch repos but delay them for two weeks” policy leads to compatibility issues with the AUR.
Also, they’ve repeatedly let their certificates expire (happened like 3 or 4 times, iirc) and there’s been some management controversy, especially surrounding Jonathon leaving.

If you want “Arch, but beginner friendly”, there’s better options than Manjaro, imho.

but it will make the planet a lot less habitable for humans.

And, unfortunately, for a wide range of other species.