Every innovative mission needs someone pushing people to do the impossible. That being said, every company trying to accomplish the impossible needs an adult in the room to ground that visionary.
In the case of Space-X, there's an adult in the room. Elon's direct input at Space-X almost set the entire Starship project back a year by insisting on trying a concrete launch pad that all of his engineers told him would fail (and it did). After that failure he appeared to get so distracted by Twitter that Shotwell could point the engineers in a more effective direction.
In the case of Tesla, there unfortunately is not. Elon's direct input resulted in canning a low-cost model in favor of a "robo-taxi" that is 100% dependent on full self driving using nothing but cameras. That's pretty obviously not going to be viable with any existing technology. An adult in the room would've told him to either stick with the low-cost model to compete with incoming Chinese imports, or use Lidar so that there's a viable self-driving vehicle that can be sold sometime in the next decade...