BTC is obviously a real alternative currency to fiat, a decentralized and censorship resistant currency, however, it is also an attractive long-term store of value, so on that note it is more convenient for most people to spend their fiat that is constantly devalued by inflation, rather than their BTC that is a store of value.
Needless to say that i do not mind spending my BTC when i get the opportunity, but it would not be on something too expensive, just a few hundred of dollars, but surely not on something that costs thousands of dollars, i'll use fiat for that.
For now it cannot be denied that the role of bitcoin has become flexible over time even though its original purpose was as an alternative to fiat but in the end until now not a few people use bitcoin as a long-term investment which makes this an added value because apart from being an alternative to legal tender (if a country legalizes it) bitcoin can also be an alternative to financial protection that we have.
This is a good advantage so that in the end even though there are still a lot of bitcoins that don't like it for several reasons but not a few people are in it because they have good confidence that bitcoin will grow in the long run.
For the problem of spending or not it depends on each perspective because in this case all have the right to spend or not their assets because those who do not spend do not mean they are completely unwilling but sometimes there are some regulations that must be obeyed because not all countries currently make bitcoin a legal means of payment, including my country which still makes this a commodity but that does not mean this is also a setback because after all this is still very good for long-term progress.