I works much better with Akkoma, but yes there are certain down-sides to single-user instances.

You mean you’ll only see content from people you follow and only people who follow you will see you content? Sounds like working as intended the way things were meant to be.

Just uses Akkoma or GoToSocial, setup fedifetcher or follow some relays and you can get good enough experience in Fediverse. Mastodon is literally build to handle huge amount of users so it is nowhere near efficient if used for just 1 person.