I wish the author had expanded on migration from one instance to another and what it entails (similar to the questions and responses here).
Another point I would've liked to see is on encryption and privacy — who, other than the people I choose as an audience, can see my Toots (the admins of the instances, someone sniffing the network, etc.).
If these platforms are being sold as "awesome", there need to be more reasons than just "no adverts and no tracking" (the latter claim is not provable without talking about encryption in a little more detail). No ads doesn't mean someone can't sell your information to someone else outside this platform. It's one thing that the owners/maintainers of many instances wouldn't sell information because of their own moral convictions that led them to get out of centralized, single company social networks. But asking to trust on that basis alone is not enough.
I checked out Mastodon quite sometime ago, but stopped using it after one or two Toots. Network effect — not knowing anyone else is a big barrier. On chat platforms, I could at least persuade one or two people I know to use them for direct chats, but these ar harder to deal with when you're looking for people who are not only local but also are working on similar causes as oneself. Like the author says, finding some interesting people on Mastodon and creating new connections could work, but it also depends on one's areas of interest. I personally also find Twitter very noisy (not in the sense of signal to noise ratio, but the amount of content). At least on Facebook I can join certain groups, avoid the news feed, etc. Somehow the topic wise discussion format seems suitable to me than a chat format (without some amount of conversation threading) with many users.