Unsolicited advice from guy who just made his first ever video essay:
If you do it right, people WILL want to learn about your niche topic of interest. I have 12k views on my first video about a long dead Australian television comedian no one my age has heard of, so, yaknow. Don't worry about a topic being too obscure.
DaVinci Resolve is a steep learning curve but it's the best free software out there. Give yourself a week or two to learn it (YouTube tutorials are your best friend) and it'll become your saviour.
Research is also your best friend. Use multiple sources, of multiple different types (essays, books, news articles, interviews, documentaries etc etc etc). I think mine was fairly well researched but I still wish I'd done more, like accessing archives and libraries and stuff like that. The more you know, the better your essay will be.
Have a thesis from the outset. If you go into it not completely knowing what your point of view is, your script is gonna be a mess. That's why I completely abandoned the first draft of my essay. Your thesis doesn't need to be complicated, it can be "this movie is really good and here's why" or "this show could have been better and here's why". Mine was literally "this comedian was gay and we should talk about it more" and that's where I went from.
You will have to kill some darlings. Not everything you research will be relevant to what goes in your final product. And that is okay.
It will take TIME. Especially if you have no prior experience. Don't expect you'll get your first essay done in 2 weeks. It might take MONTHS.
A good mic will only take you so far. Set yourself up in a quiet room, try to record outside of peak home traffic (when people are cooking, walking about, etc etc etc).
Have fun! If you're no longer having fun making it, take a break!
Anyway, if you're thinking of making a video essay and you've never done it before, I would highly recommend. It was the most fun and rewarding thing I've ever done, and I'll definitely be making more!