People don't invest in SpaceX because of space launch capability, that barely counts for their valuation at all.

The valuation of SpaceX is due to AI, namely the revenue they get for renting out their GPUs to companies that actually have AI customers, as their own AI tech has not panned out.

For the large number of companies rolled into SpaceX, they are all failed attempts to grow large enough to justify their valuations, and when a company fails to do that it just gets rolled into the conglomerate as a way of hiding the failure.

Tesla's valuation contrasted with its performance means that Tesla will likely be rolled into whatever latest vehicle of Musk's has the most attention, hiding the failure of Tesla to come anywhere near to its promises.