Kounde is 26, there is a lot of football left in him. I think replacing him would maybe not be the best move. Very rarely you can see fullbacks show elite performances both offensively and defensively in modern football. We saw him shut some of the best wingers down in Euros, we also saw him combine really well against Betis - he has it in him.
How many alternatives are there? Are they really better? I don't know. We should bring a good backup to manage Kounde's unbelievable minutes and if he turns out to be better, it won't be a problem to sell Kounde. Many clubs would love to have him.