Not sure how it can be easier to use than already supereasy web app, notifications work same via browser and you don't need to install anything, these are really no arguments for desktop app.

If you would say desktop app can do voice/video calls which you actually use (I don't, not gonna open laptop with closed lid and external display for that) I can understand using the desktop app, but for someone who doesn't need voice/video calls on computer and is fine with better camera in phone there is no benefit in installing additional dedicated app.