1) It was the first crypto coin. People associate crypto with Bitcoin.
2) It has a solid foundation. Developers made this coin with long term vision.
3) It is a good option for current investors alao because it proved its worth in last 13 years.
I agree with you, therefore nothing will be able to replace Bitcoin, because without Bitcoin there would be no altcoin or cryptocurrency, so Bitcoin will remain the king and be the right choice to be used as a long-term investment, that's why I always do DCA Bitcoin every time the price goes down, because I believe the price of Bitcoin will make a new ATH price again, so I will definitely get a lot of profit from investing in Bitcoin at this time.