Something that Whale Panda said;
"High fees and full mempool: Bitcoin is dying because it's too expensive!
Low fees and almost cleared mempool: Bitcoin is dying because no one is using it anymore"
And something that Tone Vays said;
"Why the hell, would you buy your cup of coffee, with a medium of exchange that you can accidentally put the wrong decimal place, and send it to the wrong person, and all of a sudden, you just paid 80000$ for a cup of coffee, and you can't get it back. What idiot would do that?"
We have a method for peer-to-peer transactions, it's called the fiat system (paper money). Bitcoin's main use-case is censorship resistance, this means that the government cannot freeze or seize your account, and if you keep your public address away from the public, no one except the person paying you will know that the wallet belongs to you.
Even when the lightning network is running flawlessly, and bitcoin transactions become instant and free, will you risk paying retailers with it?