blah blah blah.. hyping something just to talk about a price you hope for... (facepalm)
segwit doesnt guarantee scaling growth of doubling/quadrupling
firstly it requires EVERYONE using segwit addresses to get double+ scaling.. yet just a legacy block growth would have done it without requiring people to move funds to new address designs.
secondly, spammers can continue using legacy addresses and fill a block, thus not causing the scaling hope that you hope for..
(ELI-5) think of it like a bus, usually families buy a ticket per person one for the child(txdata) and one for the parent(signature/witness proof txdata is what it is).. taking up multiple bus seats. segwit just allows the parent to ride the bus for free if the child buys a ticket and takes a seat.
problem is if legacy families all buy the seats theres no room for segwit families.. thus segwit isnt a guaranteed fix
thirdly, the 'discount' for segwit transactions is not permanent/fixed. pools could decide to not discount segwit tx's very easily