People use their money for things that interests them, things that makes them happy and/or even to solve issues, pay bill and so on, therefore whether the person use fiat for that Tesla or BTC, I still see it as the same thing. That is, let's say the person sold Bitcoin for fiat, of which the fiat is in his bank account, and one day he decides to buy a Tesla and the money in his account is sufficient enough to buy the Tesla, which he goes ahead to buy, isn't that the same thing.
Even if the person doesn't swap his Bitcoin for a Tesla, but do so to pay bills, isn't it the same thing? When Bitcoin rises to $100k for example, will he be angry he sold Bitcoin to fiat to solve problems? I don't think so.
Many people have meet challenges which caused them to sell coins they believe in, but that's what makes us human, there are things we can't control. It doesn't make sense having Bitcoin or other coins which can help you solve issues, but Instead you held on but went to borrow.
But on the other hand, if you are selling all your Bitcoin just to acquire a Tesla, then I think it doesn't make sense and can't do such.