I think that Bitcoin is quite difficult to be used as a means of payment because the transaction fees are too high so that it will be detrimental to its users. In general, people use bitcoin as trading and investment in order to get huge profits. The bitcoin transaction fee should have been reduced so that I can use bitcoin as a means of payment in various online shops that accept bitcoin payments.
This is what makes Bitcoin decentralized. To be honest, the way how Bitcoin is being a decentralized digital currency is already a big thing for me, besides that if we have an issue on transaction fees or confirmation, there is already a solution for it, which is the lightning network.
There are also some people who are into Bitcoin because of investment, not on day-to-day use.
I have tried to use a centralized stable coin before and its fees are a bit higher than bitcoin at that time so I believe that it wasn't the high fees that make bitcoin decentralized but it was due to its nature during the time it was created. Satoshi the creator decided to have a coin that can counteract banks or such centralized payments.
The decentralized factor of bitcoin is what makes bitcoin shine because there are lots of people that like to experience freedom. Bitcoin can help them in its simple ways. Lightning network is a fix to btc issues but it is sad that it's not being highlighted because many people still prefer newer altcoins compared with it.