Now the mainstream currency, BTC-ETH, has the upper hand, and they have the strength and technology, but the future is likely to be a new project to replace them more mature and more comprehensive. What do you think it would be?
I can't exclude any possibility, personally. Time goes on and technology doesn't stop where it is. A decade ago nobody knew about cryptos, now it's all the hype. So I believe in a few years from now we will have something new. But it doesn't mean something good should go, like BTC or ETH. These will stay on.