Checking https://mempool.space, a low-priority transaction is about $5.99. That could be $50 worth of bitcoin or $500,000 worth of bitcoin to another bitcoin address anywhere in the world, with zero counterparty risk or middlemen.
Of course, using lightning, the payment is instant and cost fractions of a penny.
That's a lot of effort to increase your risk of not having a trusted middleman and pay more fees.
WIth regular systems you have a Bank, a payment processor and a sale processor which collectively provide the following experience:
1) transaction fees at the range of 0.1$ and up at %1-%3 that is incorporated in the price.
2) Visa/MasterCard etc, you don't have to choose your merchant depending on your coins you have, it works everywhere globally
3) Fraud protection is included, if something doesn't work out as expected or you simply made a mistake you get your money back easily
4) payment takes about 1 to 5 seconds and usually is hassle free, like tap a botton to start the payment tap once more to confirm the payment.
5) funds security is guaranteed through reversibility and active security, no risk of going broke when trying to listen to a conversation online.
Crytpo <> Bitcoin.
You can get pretty cheap transactions on other network.
Research Layer 2 Ethereum or blockchain like stellar are great for micro payments
Other networks are irrelevant if my funds are not in that network or the merchant is not on that network. Moving funds between networks tend to be expensive and inconvenient as you need to go through an exchange.
Transfers are also slow and too expensive for small amounts.
Moving funds costs about 20$ at the moment for BTC.