1. Institutional Adoption: One of the big factor for the recent bull of bitcoin is this. Big buyers entered the market and that increased the volume of trade that leading to price increase. What makes the difference is that institutional investors are not dumping because if they are dumping, price would have gone deeper faster after Elon musk tweet but price is beginning to stablize gradually.
Institutions could easily dump Bitcoin if they would feel like the bull market is over. They are pro traders with no emotional attachments to their investments.
2. PayPal and Cryptocurrencies: I remember this was another point that pushed price from $50,000 to the current ATH seating at $64,000. The announcement caused a spike in the market and bitcoin will keep enjoying this collaboration and for more that will come.
There's only so much PayPal can do, and they weren't single-handedly responsible for a $14,000 price increase.
3. Bitcoin Halving Driven Scarcity:Surely too , halving has been historic and such a big factor that will always cause for a new ATH, we all know this.
The next halvening is in 3 years, so there's plenty of time for a bear market for now.
4. Accessibility to the Public:Bitcoin has no restrictions on the quantity to purchase despite the challenges from countries that try to restrict the use but more means like P2P are used. So this is a convenient and decentralised financial system for the public
It has been like that for many years already.