As long as the bitcoins didn't mine all, it will stay at the top, but probably there is a high chance that it will be replaced not today but it will soon.
Maybe I should sell my BTC these days
Selling right now is not a good idea because of this current situation of market you will earn nothing but a low income. For me, do not sell your bitcoin just keep on holding and believing in bitcoin. I hope you will not sell bitcoin and just wait more time.
Maybe your are right the it is not time to sell, but you can stop someone who want to sell their cryptocurrencies because they also scared that they could lose all their entire money. I guess no one can defeat bitcoin and I know bitcoin will still number 1 cryptocurrencies.