All the FME forums, have at one time been the main focus of the scene.
Everyone has had their favourite.
The now gone MPU/Fruit Forums, was the biggest for years. It's downfall was the leaked emulator. But not overnight, but over a few years.
Then when the new era of FME started in 2016, the MPU Mecca, came to the front, when development of MFME was there.
Fruit-Emu, which had been around, had a noobs reputation, because of the amount of requests for Crazy Fruits and Deal Or No Deals, well before they were emulated. But for years, a close second to Fruit Forums and it came to the front, when Wizard started posting there and the vast majority of releases were released only there.
Then when Wizard chose here for MFME development, this site became the most focus.
Should this site close, then in a flash I'd suspect it would largely be fruit-emu, where releases were made. The Mecca crowd, are more into real machines than emulation.
Dads has nearly always been there, but largely in the background. I'd imagine only if the other 3 sites were to close, it would be the forums of choice. Mainly because I still don't think some people know it exists and has several exclusive releases.