I think that you experience is similar to that of mine (and many of Medium writers). Many writers become obsessed with getting accepted to certain publications. But this is often counterproductive, if it makes a writer stop writing.
If you aren’t accepted into a publication, find another one or just publish your article. Great content published outside of a publication is scouted for by editors of big publications anyway (as it sounds like your first article was picked up).
Writing meaningful stories (that as an added bonus function as a writing portfolio) is still the best way to use Medium imo.
But you also have been writing for a few years on Medium, in addition to a decade of prior journaling. And you still continued to write despite not striking gold with your articles.
Many new writers complain when their first few articles fail to make any money and then they give up.
I think your genuine passion and persistence way key.
As for pandemic content, yeah this has affected earnings for many. But it is still possible to write about other topics and make money. A large back catalogue of articles plays a big role in minimizing huge swings in earnings.