Web applications have become too big and heavy. Corps want to control everything. A simple example would be a simple note taking app which apparently also has to sync throughout devices. They are going to store every note you take on their servers, who knows if they really delete your deleted notes. They'll also track how often you visited your notes for whatever reasons. Wouldn't surprise me if the app also required geolocation and stuff like that for whatever reason. Mix that with lots of users and you will have loading times unheard of with small scale apps. Web apps should scale down but like with everything we need more more more bigger better faster.

> a simple note taking app which apparently also has to sync throughout devices

that is the entire point of the app, surely! whether or not the actual implementation is bad, syncing across devices is what users want in a note taking app for the most part.