I've only been working for about two years but given I'm a consultant, the travel and all is starting to get to me. Also in the long run of things, I'd love to just have passive income and focus more on my passions rather than working. Here is my current situation:

100k salary before taxes

0 debts

12k in emergency fund in HYSA

Paid off car (2016 model, will drive til it falls apart)

Currently maxing Trad 401k, Roth IRA, and HSA

Put an additional $150-200/mo in M1 finance portfolio

My expenses including rent and everything is about $1500-200/mo.

After all the above I'm still able to save money into my HYSA. I want to expand my passive income more. I don't know much about real estate outside of Internet knowledge, but I've been considering the duplex route. I don't think starting a business is right for me since I don't have a product in mind to sell. I'd love to retire as early as possible and just live on my passive income, roughly when would that be?