I don't know where your figures come from. I've seen Tesla's 2020 FY R&D expense was $1.5Bn, but that is dwarfed by the other players if the linked data is correct[1].
So apart from paying a massive premium, dollar for investment dollar you'd get much more R&D for your money buying a basket of non-Tesla automakers than tesla.
[1] https://www.statista.com/statistics/566060/automotve-firms-b...
They literally developed a completely new battery manufacturing factory and cathode plant from the ground up. Plus of course their own batteries with their own chemistries. No other car company comes even close to that.
They are vertically integrating to the point where they themselves are building their own battery manufacturing equipment.
They are even slowly getting into mining themselves. And of course solar, stationary storage and so on.
Hard to see what company is doing considerable more. Tesla is doing a pretty large amount of innovation.