To me it has always been the ease of use. I have always supported the fact that bitcoin is a great way of paying someone. I try to pay people with bitcoin and I try to get paid in bitcoin whenever I work, that is my number one option to be paid in. That way it takes almost no time compared to bank payments. Now you may think bank payments are easy and you just click some bank app on your phone to send money to someone and you are done but you are thinking just local.
I mean bitcoin makes that happen on a huge global scale. Someone from USA can send money to someone in nigeria (probably a nigerian prince for example) and it will take just couple minutes at most to arrange that. Yes there are some other things that makes bitcoin amazing but the ease of use will always be my number one reason.
The biggest help is always known easy money transfer. You can transfer millions of dollars for pennies and still have a more trustworthy blockchain behind it compared to any other method we have right now. There are even loans written on blockchain in order to make it more permenant and easily checkable right now because bitcoin and blockchain is amazingly easy to use even at a scale.
Of course this comes with a price, the function is amazing but people have been using crypto in a way that they can make money and profit from these moves instead of taking advantage of these functions. Bitcoin could have been a system for money transfer globally but instead since it is such a great project it turned into a commodity and have been like that for a while. Hence lost its function along the way since it is not used properly.