Everything is mostly being tested on the testnet chain, but the point is that if we are going to make use of Segwit, we have to move our funds away from the current non Segwit addresses (i.e send funds to Segwit address, where after that we can start ulitizing the Segwit update). If people aren't moving their funds, and just remain using Bitcoin as how they have always been using it, nothing will change, and thus they will continue to transact in the old fashion (i.e pre Segwit activation time) way. Look at Litecoin for example - a whole lot of transactions that are being sent are till this day still non Segwit transactions.