There are a few niche plugins I use for specific sites to enhance usability that I definitely don't expect to be ported to Firefox, but even the ones that are take an understandable backseat in terms of developer priority.

For example, for more than 10 years I've been using Chrome extensions that allow you to hover over image links to view them without clicking. There are dozens of these extensions in almost any browser, but they require constant updating to keep up with 1) new image/video hosts and 2) changes to existing image/video hosts.

For me, these extensions are an essential part of the browsing experience of many websites. I've found that the same extensions by the same developers often lag behind 6+ months on Firefox vs. Chrome which makes them really useless when gfycat, streamable, imgur, etc. all stop working.