Why don’t you make all your products open source?
I tried — more than 20 years ago I ran free products, and the experience went badly: support takes far more effort than you would expect, and nothing is left over for developing the product. So I deliberately prefer a smaller number of users who genuinely need the product and are ready to pay for it.
There is a second reason — quality. I intentionally keep the products simple and minimalist, and I decide what goes into them. With open source, I would have to wade through an endless stream of suggestions from strangers, most of which cut against how I see the product — and spend that time instead of developing.