Before that was one of the events that likely contributed to all the layoffs: the company’s disastrous deployment of its Runtime fee

The fallout led to Unity revamping the runtime fee and resulted in CEO John Riccitiello retiring less than a month after the runtime announcement.

Oh, they actually resigned in the immediate aftermath of that? Nice.

I'm somewhat doubtful that's the actual, or directly correlating reason for layoffs. But if you put it like that, even worse is that the CEO created that shit-show, immediately left, and one-and-a-half years later they're still feeling the negative impact.