I think when people say to but high quality items, they mean to spend what they’re worth. Getting the most expensive thing doesn’t really guarantee a quality item, but cheaping out makes it much more likely that you’ll end up with something lackluster. Plus, something like sleep can be fairly complicated and is connected to your habits, what you’ve eaten, or schedule, etc., so expecting a single change (pillow) to make a huge difference may not be realistic.
Hard to say- the Chinese govt has a long list of stuff that’s not allowed that app runners enforce heavily lest the app companies get shut down or worse. After the cute honeymoon of cultural meme exchange, Americans are in for a rude awakening if they’re expecting a TikTok experience