Tech breakthroughs won't help. There's no replacement for an investment in infrastructure. Let me explain.
I used to live in Seattle, without a car, which meant taking the bus. I thought it worked pretty well until I moved out of downtown to just off the main drag in West Seattle (California Ave.) There, the bus still worked great! Until King County Metro decided to pull service. Suddenly, all-day, all-week service from the stop by my apartment turned into 5 rush-hour trips to downtown a day, weekdays only, peak direction only. Getting anywhere else suddenly required a 2 mile walk to Alaska Junction (or, unrealistically, a local bus transfer. The 2 mile walk was faster.)
I was naive and a fool (fortunately, didn't invest much and was able to move shortly thereafter.) People who invest in areas on the basis of bus service are fools. It's constantly being tinkered with for a host of regions (fluctuating budgets, political pressures, and the damnable need for people making careers to "do something.") You cannot trust a bus route.
Tunnels or tracks in the ground, and associated stations? Those don't move. (They do sometimes get abandoned in the worst cases of nonfeasance.) One can generally rely on continued service over a period of time suitable for investment. There's no substitute for sunk costs as a signal of commitment. It's the investments in density that come with a real transit network that make the difference, not "attracting ridership with fancy buses." See yet again, Seattle. (Sorry, RapidRide is a joke.)
You know what has historically driven ridership and attracted investment in Seattle? Areas around the trolley bus lines. Because, again, you know the route's not going away if the lines are up.