So, be aware that the oldest active communities, especially those on the original server (.ml) will always get the most exposure. There are probably only ~100-300 people on the All feed in real time. The majority of users are less active and using either subscriptions or periodic most-liked feeds. It will take a lot of regular posts to attract hyper niche topic audiences. We are a relatively small community without the massive pool and algorithms to attract a audience like Reddit. Even with reddit over the last several years a hyper niche sub took a lot of persistence to establish in most instances where it was independent of some other social dynamics.
IMO, you have two options, treat a new community like your personal blog and just commit to it as such. If it turns into more, great; if not, it won't impact your mindset. Or try to find a larger genera that already exists, or create one that will encompass as large of an audience as possible.