Mastodon is "dead" because you're not making the switch from spoon-fed algorithmically-supplied content to content you have to actively seek out. Mastodon supplies tools for this, but if these aren't for you, then yes, Mastodon is useless to you.

To make Mastodon "not dead" you have to take some actions of your own to become part, in effect, of an actual community. These steps helped me:

1. Follow some #hashtags of interest. As you find people posting interesting content on that hashtag, follow them. Engage with some of those directly, responding to their posts. Do this for a couple of weeks and you'll have a full feed.

2. Occasionally look into the local feed. Skip over stuff that bores you. Read stuff that interests you. If you see the same names making interesting content, follow them. Also, engage with the stuff that interests you by responding to posts.

3. Make content as well as the replies mentioned above. Apply relevant #hashtags so it's findable. But keep in mind that the system is not going to stuff this in other people's feeds on your behalf. This isn't Twitter or any other corporate microblogging setup. You need to get followers, which you can get by following steps 1 and 2. Otherwise you're just going to get the occasional person seeing your posts who is doing step 2.

4. Boost boost boost boost boost. There's no algorithm cramming posts into other people's feeds. The only way things go "viral" in Mastodon is if people spread it around. You have to be part of the process instead of abrogating that to an algorithm designed to foster "engagement" by spreading dissent and hate.