BitcoinBTC maximalists "selling" it since 2015 as an alternative payments.
Last 3 years there were lot of adoptions of BTC Bitcoin mainly on trade markets.
But still no real daily market where the people use bitcoinBTC as a payment - just get out and try to buy a food for Bitcoin - almost impossible.
Limitation of amount for a coin like bitcoin or any other altcoin as well low inflation makes it only worth to use as wealth storage.
Gold were also a payment unit till middle of last century, but now it is only wealth storage and speculation object on market.
Same is almost happen with BTCbitcoinBTC, moreover it is to volatile to be used as payment.
Except Satoshi Nakamoto will defreeze his million BTCbitcoinBTC there is no chance for bitcoin to became real payment alternative to 100 of fiats and inbetween 3000 alternative coins, some with infinite supply.
In fact, you are probably very right in this, I am sure that Bitcoin itself will not be used to buy anything or make payments and this is because the Bitcoin blockchain is slow and that carries a large number of problems, it is not a secret for anyone , but that does not mean that a currency will be used as a form of payment in the near future.