I tried replacing the backend with just Google Firestore. Surprisingly to do this on react, it's a hell lot of code. I don't mind writing the code but it's just ridiculously complicated and hard to reason the complexity.
I thought of just bootstrap with jQuery with Firestore but then you have to do all the session management which will again devolve into a shit ton of code.
Finally decided to ditch all this and just go with Wix. Wix has definitely come a long way in terms of building websites. I can build a user registration form in minutes and have the whole site up in like less than 2 hours.
Retool offers much much more than Wix so I see a bright future. One of the shortcomings of Wix is lack of component embedding. Essentially you are limited to passing control between pages. If Retool offers component embedding, that's a huge win IMO.
Good luck folks and congratulations on the fund raise.