There have been numerous stories over the years, apocryphal maybe, but they were coming out even when the media loved Muskrat... anyway, the stories were frequently about how employees of companies like SpaceX believed him to be an absolute idiot and upper management believed that their main role with him was to block him from getting in the way.
One of the most famous stories was about some fuel tank that was fracturing in flight. The engineers had some ideas, but Muskrat came up with some idea to put a layer of fast-set glue/resin on the outside that would stay liquid - and when the cracks started to appear in the tank, the adhesive would leak out and set, automatically healing the crack. All of the best engineers in the company said that the idea could not possibly work and explained why it couldn't. Yet, Muskrat insisted on an all hands on deck and everybody worked non-stop with the vessel and the resin until... Muskrat finally acknowledged that the idea couldn't possibly work.
It sort of fits with a man who has basically failed upward for most of his life - such as how he got fired as CEO of PayPal after nearly running the company into bankruptcy with his bad ideas, but still owning a bunch of stock so that when Thiel transformed it to a profitable company and sold it to eBay, Muskrat came out with billions.
Would SpaceX exist without him? No. Would Starlink exist without SpaceX? Also no. Did he invent Starlink? Also no.
Would Neuralink exist without him? No, and who cares? It's a good accessibility play for people who can't otherwise operate a computer, but for the rest of us, do you know anybody who is loudly complaining that they don't have some shitty device in their head that will ultimately be used to shovel ads directly into their brain? Do you spend every day glaring at your computer wishing that your brain could directly control it?
For Tesla, he didn't invent it at all. Outside of having a strong first mover advantage in terms of modern electric cars, they aren't very good. Quality control has always been lacking. Muskrat decides that for full self driving, they don't need industry-standard tools like proximity sensors, but instead they'll rely only on cameras. He did, apparently, invent the truck that looks like a small child drew it and which is almost universally reviled. So yay.
Otherwise, what has Muskrat invented? Hyperloop - the dumbest mass transit invention in the history of humanity? 12 years later, there isn't a single operating hyperloop that you can go ride. And it turns out that vactrain concepts had existed for years before he "invented" that too. So... has he had a single novel idea in his entire history? Or is his "genius" really just in ways to exploit existing wealth to extract more money, mostly from the government?