If you are a business owner, you will have to ask yourself what's the point of accepting a currency, which is valued at 20K USD in the first year, goes above 60K the second year and it drops to 15K on the third year?

The business owners want stability and predictability and Bitcoin is anything else but stable and predictable. Adding BTC/crypto payments just to convert them to fiat money right away doesn't make any sense. The crypto demographic isn't that big, It's probably less than 0.5% of the global population. No business would break a leg and an arm in order to please a few hardcore crypto enthusiasts.
Tesla is a "government baby", that would have gone bankrupt, if it wasn't the US government supporting them. I can't take this company seriously.
There are businesses that accepts bitcoin just for the sake of bragging that they know about it. It boosts their popularity and attracts some customers that are also pro-crypto.