Rollout of Wayland has not been the smoothest and I think among its major issues is the slow pace of development - it took it 10+ years to become default and certain features present in X11 are still missing. Having said that, after I switched to KDE Plasma 6 with Wayland (on Intel and AMD graphics), I've noted a significant improvement in responsiveness and snappiness of the desktop. I know nothing of how Wayland works, but I assume this is the reason the replacement was needed in the first place. I had to replace my GPU from NVIDIA to AMD, but I don't regret it (all my deep learning compute is on the HPC cluster anyway).