You are correct, Bitcoin is an investment even though some countries has now legalize it as a legal tender and some supermarket now accept payment with Bitcoin even buying properties a lot of people prefer you pay them with Bitcoin, however a lot of people won't trade there Bitcoin just to buy things in a supermarket or buy car this is because Bitcoin has the tendency of growing to a more bigger money for them so they prefer paying with there fiat currency than there Bitcoin.
Of course, if I talk about holding, then El Salvador will come to mind, because El Salvador has been holding Bitcoin since 2021. And you mentioned the country of El Salvador where Bitcoin has paid transaction fees and the government does not have to pay any taxes. Because the legal tender section has accepted Bitcoin as the main currency of that country, so the country has provided benefits to the people in every way for the benefit of the people. He has constantly taken sufficient steps for Bitcoin education, but his country's Bitcoin holding system is very good and will hold more Bitcoin in the future.
However there are some people who can see paying with Bitcoin as no much a big deal and that is those who has reached a fuck you stage where they have accumulated enough and can even decide to quit there job and live by there Bitcoin investment.
You can't expect someone who is still accumulating Bitcoin and has not Accumulated enough to start using his Bitcoin for basic payment, I know some people do it but such persons are not Bitcoin investors.
But if we talk about holding, only those who hold it for the long term can be included in the scope of Bitcoin holding. There are some people who receive and sell Bitcoin for a short period of time and they cannot be included in the scope of holding, but holding is those who will hold it for the future, such as MicroStrategy Company, the government of El Salvador, Nayib Bukele, and those who hold Bitcoin following the DCA method. All these investments are generally included in the scope of long-term investments, and they will increase their holdings more in the future. So basically the current time is still a very suitable time for Bitcoin holding.