There are three parts of building products in software just like everywhere else:

1. understanding what product needs to be built

2. Having the technical expertise to build them

3. how much effort is needed to build it

And all three things can be hard in themselves. The product can technically be just straightforward (even if somewhat tedious) but you should know what to build because you should know what the customers need.

The product can be technically so challenging that without the theoretical background, you would not even know that such a product would be possible. (An example here would be something say that requires distributed and independent time clocks).

Finally the product can be something that is technically simple, obvious in its customer demand but requires quite a bit of effort and therefore requires you to be good at procuring resources and managing them.

You need to figure out which of these three things made you successfull with the product you call really hard and interesting and pursue that line of industry (even if it is not software!). And then slowly try to become good at other two things.