As I answered on a previous thread for this topic, after bouncing around several 3rd party clients (which are all just electron "apps" loading web.whatsapp.com anyway) I settled on using ungoogled-chromium to "install" WhatsApp as a PWA.
By using separate profiles, you can "install" just about any website you want as an "app", each with separate cookies, history, extensions, etc., so it's quite good for privacy, and you only have to trust the rather renowned ungoogled-chromium instead of various random people making unofficial programs for WhatsApp, Spotify, Netflix, etc.