My suggestion is that you look at building a NICHE as a “side hustle”. Treat it like a completely separate business in the beginning. Invest in it. Build a goal around it financially that does not address an immediate financial need. For example, " I am going to pay off my mortgage in 7 years instead of 15 with the commissions I make off of this building. I am willing to be patient and do it the right way knowing that if I stay at it, I will be successful”.
Building a NICHE has a tremendous ROI potential is difficult only because it does take patience and consistent effort. Again, your NICHE can be all kinds of things: A specific building/neighborhood. A specific talent/expertise. A specific product type in specific price point. A specific demographic.
Identify your “super power”, invest in it, water it, be patient, become an expert, be consistent and repeat.