As someone who has done bug bounties and also has certifications, I can suggest a few things.
1. College - Like others said, it helps a lot not just careerwise but socially as well.
2. Try joining big security groups/org - You have a lot of knowledge, especially in RE/PWN fields so maybe try joining organizations that do security research full-time example Google Project Zero or there are loads of other organizations that does that kind of work. This will make life easier in sense of what you wanna do. By joining such groups/organizations you can choose to work on game engine/cheat-anti-cheat hacking or browser/OS security basically choose what you wanna hack.
You might think why would you need a job in any org to do so? Well, simply because a stable income(the reason I stopped doing bug bounties) and association with a good org/group improve your network. Not sure if you know this or not but having a good network of people really helps, professionally.
3. I saw someone mentions that you should think of getting certifications. Believe me, when I say it, certificates do nothing. I got my OSCP because people said it would help me get a job, but it didn't. Certificates are only for people who don't really have anything else to show or beginners in the fields trying to get their foot in the door. You already have an amazing profile showing that you are capable of doing RE/PWN stuff. Go for certifications only if you actually want to have fun and take on the challenge. Don't expect much change in your professional life from those certifications.
**
You already know this but I'd state it again, literally every program lowballs, and no one wants to pay up. So if you get 10k for RCE but expected 100k, just stop reporting to that program. If you like working on their services then maybe try talking to the program managers about it. In the end, if you feel like the program isn't giving back as you expected just move on to a different program.
All the above stuff was what came to mind to help your professional/bug-bounty career. To answer the question
> I've been told many times that I am low-balling myself and should get into smart contract or browser security. Please let me know what you think and feel free to ask any questions.
If you just want big money, yes smart-contract seems to be the big hot thing. If you are looking to make a big name in the security field along with a decent(sometimes really good) amount of money then browser/OS security is definitely a good thing. In the just try them for 1 week/month and stick with something that you enjoy :)
Happy hunting!