Slot limits aren't bad and not having slot limits isn't always bad either.

>>4 Is mostly correct, think of it this way, when you send someone a letter you put it an an envelope right? If you can only send 100 grams of letters at once and each envelope has a mass of 1 gram and each letter is 10 grams, you can only send 9 letters at once. Stuff over the internet needs envelopes and addresses too.