Fabric is great for quick and efficient mods updating every snapshot but lacks content. I mean content like quark, Redstone paste, abyssyal craft, tech mods, etc. Most modders on mods listed have stated they will be staying in forge.
Forge has above mods but lacks speed.
This poll is derived to show that I feel that fabric API is going to die out due to these common issues. I could be wrong, but which mod API are you going to stay on.