including security? auth? database design?

In my life, its not as long that I can fill each discussion, I've seen quite a few situations, where I said "thats it. Thats an perfect idea no one have had before" -> nope. Each one turned out to be not as good as I thought and, I wasn't the only one who came up with that... My experience tell me, you need a differentiator. You have to solve a pain, but the medicine must be better than of your competitors.

In your case, I would rather say "if the others, like you, are really solo-interpreneurs and do exactly the same thing as you do. Then it will be ok, as long none of the others start to invest heavily in marketing with a dedicated marketing department. That will be the differentiator that might break your neck."

Stop dreamin, reinvest the gains and employ some people to bring your business to a new level. Don't risk it without necessities. Dont slow down your pace with "principles". My opinion.

I may be wrong, but I'm a different risk profile. I like to have everything under control. What is your risk taking capabilities?

may be, this will be some kind of inspiration. That guy build and sold for 100mio as a solo:

https://www.youtube.com/watch?v=AR2H7X1HBEM

I know nothing about product, but think how many people could have done it with the same tools as you.

Nothing new under the sun.