That's the only part I don't like about the Switch OS, and, yes, it's very bad. And it always baffles me why they wouldn't improve the app that generates revenue of all things.
And you can only buy one game at a time, and have to enter your password in for each one? I like to do all my game research and shopping in one evening and buy 3-4 games at a time. If there's a way to do this I would love to know how!
Have you scrolled through the Switch store? The UI freezes for seconds at a time while network requests lock up the main thread.