Low volume niche can be unprofitable yeah, but that's if you pick a bad one. There's a company out there that makes high priced, high end children's bedroom decor. $150k in revenue just from 130 customers. All from social media. Niche, low volume, but high return.
There are plenty of niches out there. The more specific it is, the less competition, but not necessarily the less lucrative. Be a 3D printing affiliate. There's one idea. Very specific niche and not many affiliates, but 3D companies and their stocks are booming. Great industry.
Just think instead of whining.