Google was impacted: their chat product is pretty much dead.
replyMobile network operators lost the profits (at prices that were pretty much pure margin) they had on pay as you go messages, and messages not included in flat plans (e.g. overseas SMS's). They also lost a huge amount on highly profitable overseas calls. Those of us with family in other countries save a lot of money by using Whatsapp and similar instead of phone calls.
WhatsApp and other over the top messaging and calling apps destroyed “the rivers of gold” that the telcos had in the late 1990s and early 2000s.
replyNet neutrality was triggered by their attempts to block VOIP and messenger apps.
I knew one telco who made €3Bn clear profit a year from 2 Dell servers and a team of five to keep SMS messages flowing. Their billing infrastructure was bigger, much bigger than the SMS servers.