I think it would be great for KDE to accept donations through Liberapay.
Hi - just to double-check that you’ve already seen this: If your interest isn’t necessarily specific to Liberapay but in wanting or needing to use a method other than PayPal, there are several other donation options available by starting with links at this page: Donate and support KDE - KDE Community 
Yeah I’ve seen those. It’s mostly that I’m just not comfortable donating through the provided methods (eg PayPal Donorbox etc.).
Anecdotally, Liberapay has shown themselves to be rather ethical, imo, so I’ve taken a liking to donating through them. It would also be convenient for me personally as, by my experience, many other organizations and individuals have donations set up for Liberapay, so having KDE on there would keep all donations nicely grouped into one service rather than spread out over many.