I've personally helped a couple brick and mortar shops start accepting BCH, so it's not that I think it's a total waste of time. To the degree that anyone happens across that store and sees a little sticker saying, "BCH Accepted Here," it helps to normalize the existence of BCH in this world.
But, that's about the extent of it. In terms of demonstrating any particular advantage of using BCH over cash or credit, BCH is too late.
There might have been a brief window where the QR code payment system that you use in almost all BCH applications was more convenient than fiddling around with cash and coins, and you could make a case it was easier or faster than a credit or debit card.
But while crypto is constantly developing, cash hasn't stopped evolving either. Now, every advantage that BCH had in practical terms is spread out among lots of competing fiat based services. And those services come with significant advantages that make them much more appealing to use than any BCH wallet.
I say that as someone who supports and believes in BCH. But I don't use it for buying anything at the cash register.
I don't know what it's like where you live, but where I live, right now, in Japan, regular money is decidedly better than BCH for day to day purchases. At least, it is if I use one of the many competing services that are vying to become the defacto electronic money. Here in Japan, they call them "cashless" services, meaning you aren't using paper and coins, even if technically you're still using cash by proxy.
I use two of them regularly. Technically, I use three, but the third one, called Suica, is just an RFID based cash card for storing yen, and the details of how it works aren't so important for this discussion, so I'm going to leave it to the side.
There are two services that I use every day that I want to draw attention to. One is called PayPay, the other is Line Pay. Just like my Bitcoin.com wallet, they use QR codes for sending and receiving. In terms of speed, interface, and ease, it is exactly the same as the Bitcoin.com wallet or any other BCH app.
Better than my Bitcoin.com wallet, though, is that I can charge up PayPay or Line directly directly from my bank account or credit card with the press of a button. Or even set it to automatically recharge if I wanted. Also, I can charge them with physical cash at any convenience store. Without any service fee, either. If I take 5,000 yen from my bank account, then I have 5,000 yen in my PayPay app. No service fees. No trading on online exchanges.
Further, I get discounts, promotions, and incentives to use my PayPay and Line wallets. PayPay ran a campaign that I did very well by, getting up to 20% off all my purchases for a period of about six months. I also won a contest they ran. I still get very minor discounts. The Line Pay app offers similar points back all the time, plus they send me so many coupons that I can't keep up.
This all may change. Right now, in addition to the two I've chosen to use, there are literally dozens of similar "cashless" apps competing to become the standard in Japan. So, all the companies backing them are offering deals to both consumers and merchants in order to push adoption. But, when the market determines who the winners and losers are, there's no reason to suspect at the moment that there will be any significant drawback that makes these services any worse than a credit card, debit card, or any crypto.
And, of course, one huge advantage these "cashless" apps have over BCH is the absence of the volatility of BCH price. Any time I purchase anything with BCH, I partly have an eye on whether or not I'm effectively paying more or less than the price I'm seeing in front of me, because the value could change literally within hours.
Which takes us to the most important point.
Even if the volatility were no longer an issue, then the best BCH can hope for is that it would be the same as how cash works for me now. That's it. No better in any way except maybe some esoteric concern about privacy.
Look, I take my privacy seriously. I use Tor and VPNs and have multiple email accounts for different purposes, so I'm right there with you when you say that people should be mindful of their privacy . But at the same time, I don't give a shit if the CIA knows I bought an oat milk latte from Starbucks to drink while I wrote this. Good security isn't about being constantly militant, it's about knowing what trade offs matter.
At the moment, unless some upcoming feature that I don't know about changes the game, the best BCH can aspire to is to become just one more face in the crowd of payment options. No worse or better, and therefore nothing to drive it's adoption. You don't beat anyone by just being the same as them.
One way to get around this is to try and think of ways that BCH could be better at handling payments at the cash register. But I think that's solving the wrong problem.
I think the better question is to ask, where can BCH naturally win where current payment options struggle?
The answer to that is, and always has been, micropayments online. Banks will always have institutional overhead costs that will make it hard for them to be cost effective at online payments under one US dollar. Cryptocurrency's near complete lack of middlemen can fascillitate payments in fractions of one US cent.
If someone develops a killer app or game using BCH for transactions in some way or another, BCH could rocket into position as the defacto online currency, taking over space that other payment systems don't have any ability to compete with. That's where I believe BCH's future success lies.
Every few days I see a post on r/btc about some restaurant in Australia or Tokyo or somewhere now accepting BCH. Usually in the caption they'll say something about how this means BCH is "winning". I guess it is a small victory, and that's nice.
But if I see people making apps with micropayments handled by a token built on BCH, then I'll know we're really starting to play the game.