Perhaps your definition of hobby is different to mine, but hobby projects are exactly the kind you can abandon in a heartbeat. No long term customers, no guarantees, no obligations. In fact, we hear about countless HW and SW projects being abandoned left and right, right here on HN on regular basis.
> For that time cost, I want to work on a product that could go into production and pay for its own maintenance.
Hobby and high volume production aren't necessarily mutually exclusive.
I wanted to build a custom board to use USB-C power in my projects. Except the cost of a dozen boards assembled was quite high. So I made a thousand or so to subsidize the cost of development and production for myself. The chip I used went out stock (global chip shortage related) but until it did, my "hobby" project paid for itself and actually made me a small profit as well.