Ask HN: Is it still worth selling technical courses?

I want to make money from a product but I don't have a good idea for SaaS or anything physical for that matter.

But I have niche technical knowledge such as blockchain, cryptography, functional programming etc and a knack for explaining it well.

I figure publishing and selling a technical course is a good intermediate step towards making money outside of a job.

Is there still demand for technical video courses out there or is the market flooded?