Yeah in honestly shocked at how many niche problems. I encounter that have ready solutions. If I ever find a truly unsolved problem, in likely to assume that its just too hard to properly solve at the time.
Why do you think you need to find a truly unsolved problem? If all you want is a profitable, sustainable business, look at what companies are already paying for, and build a product that solves one of those problems. It doesn't have to be a carbon copy of an existing product. You can differentiate by price or combination of features. Or you can target a different niche. Competition is a signal that there's money to be made in the market.
It won't be easy, and you will have to learn sales & marketing. But it is doable. If there are X companies in the market, there's likely a place for another one (as long as this isn't a winner-takes-all type of market).