If you're thinking about setting up your own single-user Mastodon instance for similar reasons, I urge you not to do it. The user experience is so broken that it's baffling that anyone would find it acceptable.
Everything the author points out in this article is indeed a limitation of hosting your own instance, and I do agree that most people should not do it, but…
This feels like one of those things where one person's needs do not reflect the needs of everyone else. no, I don't have a useful trending topics section, but I despise trending topics, and even on mastodon.social they were so banal that they were completely useless to me. Likewise, following hastags sounds like hell to me and I would never do it anyway, so its omission is not even something I think about.
I personally treat Mastodon very similarly to RSS; I follow who I know I want to follow, and all discoverability of new accounts comes from those people linking to and boosting other users. I appreciate not everyone will want to use it that way, and that’s fine, I like that Mastodon (ActivityPub) gives me flexibility to get the experience that works for me.