I really don't understand why we need to absolutely ruin desktop UIs in order to have mobile interfaces. For web UIs it may be argued as a necessary evil as designing multiple front-ends is expensive and reactive UIs can theoretically be made to exist and shown in small demos to be decent, but when designing desktop applications?

Having a framework that can be adaptable, like GTK, allows for padded, but IMO reasonably-sized touch targets. Designing an adaptive desktop app means the effort is only spent once, but can kickstart the virtuous cycle of "Mobile Linux is less trash than it used to be" -> More users are willing to use Mobile Linux -> More effort is spent making it less trash.

Though if you insist on click-targets that are exclusively for the mouse, I've found most KDE apps less mobile-optimized. The elderly and mobile users can appreciate larger touch-targets, and you can avoid GTK, which seems like a perfect compromise