I think there's something to be said about building something simple of value and selling the crap out of one idea.(Assuming you know the idea brings in some kind of value for customers)
This kind of thing is easier to do than people give themselves credit for. Half of the problem is just getting yourself to practice it. You'll fail a few times, it comes with the territory. You might be more comfortable doing freelancing and transitioning to product, but both can be done.
That being said: business is of course significantly easier with help. It can be hard to bring someone on board without at least putting in the initial effort if you were going to do it by yourself anyway though. So it's a really good thing to attempt regardless.
The best salesman are the ones who don't know how to say no. I think the self defeatist mentality of "I'm not a salesman" is the core problem. You're a salesman if you call yourself one. The main reason being: You're the first person who said yes. Your next job is to do what every other sales person has to do: stomach a no answer, learn from your mistakes, and iterate on your idea within reason of making sales. Validation is apart of the sales process as well.
I haven't updated it in months.
Need someone to physically pitch your product to investors? I can't do that.
The thing that will determine your success is sales and marketing, especially early in the business life.