Cohost, bless their heart, seems to be trying their hardest, but discoverability here is... low.
I gather that some of this is intentional as they aim for a lower key, less competitive, less popularity-driven community.
All the same, posts aren't searchable, people are only searchable by username, and there are no algorithms that display trending topics or make suggestions based on your interests. New people have a hard time connecting with others, and our main option is to either connect outside of cohost and exchange handles, or do mad hashtagging into the void.
So hashtagging it is.
If science, science communication, and science writing are among your interests, please comment here, and that way the world can find you.