Even if Bitcoin and Tesla were in direct competition with each other, there would be space for both to co-exist. Ethereum is an excellent altcoin, it has contracts and is modelled differently to Bitcoin. The same for USDT or DAI (regardless of 1:1 ratio potential pitfalls) and also XRP, they have their own benefits to bring to the table and all are co-existing.
I suppose if you were an investor with a few thousands to invest, in that case there could be a dilemma about where to invest if you narrowed down your shortlist to just Bitcoin and Tesla

But the Goodnews in this term is that, there is actually no competition between tesla and bitcoin, anybody with a properly working brains would know that in the near future, Bitcoin will be sitting among the top 5 assets with the most market capitalization globally, tesla cannot compete with bitcoin in this regard, this is very certain and not a thing to be surprised about.