About 5-6 months I was also don't know about segwit wallet of bitcoin , but when a signature campaign in which the manager made a rule to use segwit address mendetory to receive payment then in that case I was restricted to use this wallet .
At that time I was thinking in negative way about campaign manager , but when I used that address for the withdrawal of btc at low fees then I found that campaign manager who restricted me to use segwit address is very right at high place and I thanked him by heart for this rule Because this wallet saved about 0.01 btc yet from the fee saving .
But here it is strange that why not people still with these types of post seen , are not going with this wallet .
In my opinion every exchange should use this wallet for the withdrawal of btc of the users Because they charge us 0.0001 btc 0.003 btc which is very costly for traders like us , so if they can implement segwit wallet in Thier exchange than in that case we can have better turn in trading in exchange for small small btc amount trading with more profit ( specially in case of arbitrage trading ) .