But that's just qualifying. Racing is about so much more. Driving software will have to integrate considerably more inputs in order to avoid crashing into other cars. Let's say cars have to share telemetry. Development could probably happen in parallel with other improvements but I'd still stay 3-5 years.
Even if we assume software that can drive in a pack of cars, and algorithms for attacking and defending, there's that drive to win that makes some drivers do things that, if we're honest, aren't fair, safe or even right. The rules are different when nobody's life is at stake.
I would love to see Formula 0. No worries about driver safety. No artificial design limits to reduce cornering speed. In fact, the only design rule I would impose is the maximum height above ground and perhaps something about no laser cannons.
Does anyone remember Rogue and then Rog-O-Matic? It would be fun to create an online competition using an existing racing simulator.