That page only lists browser engines it thinks are “notable”, which is not the same as viable. Microsoft stopped developing its own engines when it moved Edge to Blink.

Currently there are four viable browser engines (still being developed and capable of displaying enough sites with enough accuracy to make a plausible daily driver) in two families: WebKit and its fork Blink, and Gecko and its fork Goanna. Goanna is not corporate. In addition, there are some experimental engines, like Ladybird’s.

I won’t deny that the situation is dire, but it isn’t quite as bad as you’ve painted it. Yet.