Really, what difference does it make if it is cheaper for merchants but buyers are still not going to use it anyway and partly because it is too costly for them to transact with it
Because I reject the notion that it is "too expensive to transact with". With bitcoin, I can pay someone $100 for a couple of cents. I can pay someone $10,000 for a couple of cents. I can pay someone $1 million for a couple of cents. That is hardly "too expensive" for the buyer
The devil is in paying precious attention to detail (not my phrase but I like it)
First, to begin with, you don't pay a few cents for a transaction unless you are willing to wait a couple days till your transaction finally gets confirmed (I've done that and it doesn't work good). Further, most everyday expenses are below 100 dollars per purchase even in the US (it is easy to figure out why), so even a few extra cents for a cup of tea may look or feel not as appealing as paying nothing above the price tag
Apart from that, those who send 1M dollars don't particularly care about transaction costs, while even with wire transfers there is an upper limit on fees, which rarely exceeds a few (dozen) dollars (pretty much like your few cents per Bitcoin transaction). And if you are not money-laundering or doing some other nasty stuff which may land you in jail, fiat transactions can be more attractive, especially if your goal is to move fiat, not coins
That's without even touching on all the other benefits of bitcoin, such as being faster, protection from chargeback, privacy, no KYC, no third party telling you what you are and are not allowed to spend your money on, and so forth
As a buyer and consumer, I would definitely prefer chargeback rather than protection from it
I think if more people realized the advantages of bitcoin over the fiat system, then yes, it would help adoption
Most people are living paycheck to paycheck and often in debt at that, so those advantages (even if they are real) are of no advantage to them (pardon the pun). And that is not going to change in the foreseeable future