Cryptocurrency aims to solve two problems found in fiat, The Value Problem, and The Technology Problem.
Bitcoin was an over correction to the first problem, a supply cap doesn’t solve the issues with fiat, because the problem with fiat isn’t supply, the issue is at which rate supply is generated, in the fiat world fiat is created in excessive amounts.
In a way Bitcoin is the opposite of MMT.
Bitcoin also seeks to improve the technology problem by making value transmission faster, and more effective, and Bitcoin does solve that over the current system in most aspects, it transmit value faster, and more effectively than fiat systems, however the fiat systems are delayed intentionally to stop terrorism, money laundering, and double spending, etc., whether that’s a good thing, or bad thing is up to debate.
That being said Bitcoin is more effective than the current fiat system at maintaining value, and transmission of value, however based off of economic principles such as velocity, and supply, Bitcoin fails, since Bitcoin becomes too valuable to use as a Medium of Exchange, and while Bitcoin solves the technology problem, other technologies like XRP, and Monero solve it better but yes the counter argument could be that lightning is also sufficient as a global transmission layer.
I think the practicality of Lightning will be used as custodial services if adopted by the masses but that is counter intuitive to money which is developed to be against centralized entities (malicious or not).
Bitcoin is too valuable, Monero is valuable enough to spend but not so valuable that it can be replaced.
If I lost 1 Bitcoin I would be devastated due to the absolute scarcity, however if I lost 1 Monero I could easily recoup that in 4 minutes of mining (assuming I hit two blocks successfully solo mining).
My debate is focused around Medium of Exchange, not assets, or global reserves, and while money may benefit from that, I think Bitcoin is a sort of stand in/proxy for cryptocurrency at large.
I acknowledge Monero will not become a global reserve assets in publicly audited ledgers, however I assure you the Department of Defense will utilize Monero for their Black Budgets.
But we can argue semantics, it appears we have two different reasonings/logics, which is why our disconnect in debate keeps occurring.