Pore is substantially different from Phoenix.
The design of Phoenix is basically just an abstraction layer over both Sponge, Spigot and potentially more.
Pore was flawed in that it was trying to make Bukkit compatible events over the Sponge events which just wasn’t going to happen as they are fired in different places.
An abstraction layer like Phoenix has the possibility of succeeding, but needs a solid team behind them.
WorldEdit, CommandHelper, CraftBook, NoCheatPlus, are several plugins that have used abstraction layers successfully to work over multiple API’s or Minecraft internal versions.
That said, There probably is several others doing the same, WetSponge comes to mind as one I’ve seen on Spigots side that supports Sponge. There are probably more.
As for people that go, “Please just support Pore”
Pore was doomed, Phoenix isn’t, provided they can stay maintained, and maintain trust.
It would be easier to make an alternate server platform, that implemented both Bukkit and Sponge then make Pore using only Sponge.
Additionally you need to consider the crisis that caused CraftBukkit to self-DMCA.
Bukkit is GPL Bukkit/LICENCE.txt at master · Bukkit/Bukkit · GitHub. Minecraft code is not.