My company, https://talkjs.com, is in the same market as Cord was. We let you put a full-featured chat UI inside your app; you control all the details and we handle the realtime infrastructure and scaling up.
At the time we were rather surprised when suddenly, seemingly out of nowhere, Cord popped up as a direct competitor to our product. We were even more surprised to find out that, only a few days after we learned about them, they had discontinued.
I just gotta say that not everything the author shares resonates with me. Notably the idea that devs really really want to code chat and commenting from scratch. Our customers generally have plenty of competent developers on staff, and these devs all have plenty to do and generally they just don't want to waste time building an entire WhatsApp clone inside their platform/marketplace/tool/whatever. They'd rather spend that time working on unique features for their market instead.
We do, however, need to convince developers that they can control everything they want to control. If they get only the the slightest idea that we're either bullshitting them or simply not letting them build what they want to build, the conversation is over right away. I suppose this holds for any product that sells to devs though (or one that sells to PMs but is, in practice, vetoed by devs).