I've decided to permanently stop contributing to all Stack Exchange sites as of 30 September 2019. I give more details here. The high-level reason is over the course of the last two years it has become completely apparent that Stack Exchange no longer sees its community as a partner. That means Stack Exchange is simply an exploiter of that community, and, worse, one that it treats with contempt.

It is commonly pointed out that contributions help people other than Stack Exchange too. I agree, and contributions in other venues and on other platforms will help people too. At this point, I don't think anyone should be contributing to Stack Exchange. If people arrive here with good questions and fail to get answers, they will simply move on to alternative platforms which is exactly what I'd want them to do.

It is possible for Stack Exchange to regain most of the trust lost, but that process is one of years from when they start the process, if they ever do. By that point, however, I will have quite thoroughly moved on.