At least the last two times I’ve finally succeeded through remembering the existence of https://man.sr.ht/, which does have a (different) list of services, and only when writing this comment did I stumble upon what is probably the intended way—that https://sr.ht/ (my first try every time, and what “sourcehut” in every header links to), which looks like a Sourcehut-the-website homepage, has a link in its body, titled “Sourcehut”, to https://sourcehut.org/ (previously located only via a search engine), which is seems to be the intended Sourcehut-the-website homepage, and presents it thoroughly and eloquently.
Now that I’m looking at this closely, man.sr.ht mentions “service[] links in the navigation at the top of the site”. Those probably eliminate this problem for logged-in users—but I’m not one of them, so(?) I don’t see any!
A somewhat related complaint is that the git.sr.ht page for a project (that I’m most likely to remember, because they’re in my git remotes) don’t link back to the sr.ht page for it with the ML and CI and perhaps sibling repos (that I can in the common case reach by simply editing the domain of the URL—once I remember it exists). I wouldn’t be surprised if most people unfamilliar with Sourcehut, when visiting a git.sr.ht link, thought the repo on it was all there was (especially given it would be true on GitHub).
(All of this is reasonable given how Sourcehut is factored into several services, but it’s still unfortunate.)
TL;DR: Sourcehut nice, Sourcehut homepage also nice but difficult to find when pointed to hosted project’s home or repo page, former also nonobvious from latter.