Segwit is still not fully supported in the Core wallet [1] - change goes to P2PKH addresses and there's no GUI support for generating (or even sending to AFAIK) bech32 addresses.

While certain charts regulary show 10% usage [2], when analyzing UTXOs, the numbers are a miniscule 0.03% of transactions. [3]

[1] https://github.com/bitcoin/bitcoin/pull/11403

[2] http://segwit.party/charts/

[3] https://twitter.com/dukeleto/status/954759096544124928