BUT now I'm curious. Why does segwit take up more space?
A simplistic explanation would be that Segwit isolates transaction witness data; only the actual transaction data is counted towards the original 1MB limit, so 1MB + witness data could result in blocks bigger than 1MB. The "true" block size limit is now 4MB including witness data.
Ohhh, so segwit actually duplicates data that's already there in order to separate out the transaction data without the extraneous signature data or whatever extra data. So it actually causes redundant data that would screw the blockchain's exponentially as it grows...