Two questions regarding FireFox ESR for legacy macOS:
Is there any plan to make Yelp compatible with FireFox ESR? It hasn't worked correctly for a couple of years…
With the conversion from Intel to Apple Silicone macs, any idea how much longer will FireFox ESR support the Intel platform?
Alla svar (2)
Correction: To make FireFox more compatible with Yelp…
Your Firefox reported itself as version 78.15.0esr. Firefox 78 hasn't received any changes for a few years, and isn't expected to receive any in the future. Someone will need to figure out a new workaround for Yelp based on whatever its problem is with that old version, if that is possible.
Regarding support for Intel silicon, I don't think that would be discontinued any time soon. But even if, say, hypothetically, Firefox 150 for Mac stops supporting Intel silicon, old versions of Firefox wouldn't be affected.