Except I also see crud apps that take 8 seconds to load, and you can't just fix it with a cache. EVERY app has performance considerations. Literally every app. Some may be very loose.. but then spell it out, and use that to think about it.
If you're following basic REST guidelines regarding idempotency then, yes, you can "just fix it with a cache." That's the whole point of the guideline. Updates can still take awhile, but you can fix that if you need to with a backend jobs server.
Performance should always be in your mind somewhere, but it doesn't always need to be at the forefront.
Unless it's taking 8 seconds to load because your user is on 2G. Then the only way you can avoid that hit is by not making the requests in the first place.
