Let's see how one operates before condemning it, no? I personally don't have the slightest clue how it's all going to work. I'll wait to see one in real life before deciding.
Go try Ripple (if you dare), they have "lightning network" called "payment channel". I used Ripple in 2013 and it's terrible and I won't use it ever again. Maybe it would be a good introduction how hard would it be to live in a centralized crypto. Problem with centralized is that you are not free, you must obey by their rules, for example bitcoin exchange website can freeze your account, block you until you get verified etc, same could happen in the centralized crypto world.
There will be other crypto-currency solutions, I didn't say that crypto-currency is dead, bitcoin is dead because technically it's heading in the wrong direction. Blockchain is the only true solution, avoid everything offchained and centralized.
I expect that the future of crypto-currency world would be in concurrent blockchains, find one that is cheapest, fastest, most secure etc, blockchain usability would dictate blockchain's crypto-currency value.