If the price goes back down again to around $4000-6000, people will be able to buy whole bitcoin, I know people can buy fraction of bitcoin, but buying whole is a better deal.
Buying bitcoin now is still really expensive. Buying whole one is hard so people just buy fraction of it. If the price will decrease to 2.000$ then we can buy whole bitcoin again. This time, it is better to invest in altcoins because they are affordable then kater you can trade them for bitcoin.