I think the future is smaller self-driving vehicles. Brightline will be facing some headwinds: If they need to borrow more, interest rates are going to go up sharply, and fewer people will commute post-covid. Also needed for success is reasonable insurance costs.
Self-driving vehicles are still at least around a decade away from being fine-tuned, not to mention what kind of regulatory and legal battle they will face when they hit the market en masse. I'd also imagine they would be exorbitantly expensive for a while, just like how electric cars are still expensive compared to their gas-powered cousins. It's going to be at least a few years of generating a decent electric used car market before we start seeing more of them on the road.
I don't think it's really fair to judge Brightline's model at this moment until Orlando opens up. Interest rates going up or not, they are very deep into their South Florida operations and seem to be doing well there. Brightline's use of their property for smart real estate moves is definitely helping keep the company afloat, but I think they might not even need to rely on that once they get Orlando open. The interest rate thing will definitely affect Brightline West, and it wouldn't shock me if it goes belly up as it has with the other 2 or 3 operators beforehand.
I don't think Brightline is shooting for commuter service (with their own money at least, they are partnering with Broward/Miami-Dade counties to have some sort of commuter service on their rails), I have not heard of people commuting between Orlando-Miami-Fort Lauderdale. They are aiming for the large tourist market Florida has, and if you can get Disney people to the beaches and vice versa without them needing to fly again or rent a car, you're talking about huge potential