Such an idea would be remarkably pointless but I wish you luck in finding such a server.
I do know that computer craft servers are a thing so I guess it's not that outlandish. But most FTB packs are created for building machines with purpose in mind. Then again there is a host of esthetic mods like chisel, Carpenters Blocks, microblocks and those few design blocks various mods add in.
What's pointless about having a group of strangers building beautiful things together? I once saw a Vanilla creative server build a scale model of the USS Enterprise. Just imagine going back through that and adding working computers, replicators, turbo lifts, and teleporters. Imagine the aesthetics you could add with mod blocks, pipes, and lighting options.
On the other hand, what's pointless about a group of people getting together to build massive rollercoasters or crazy perpetual motion machines? As long as like minded people are having fun, there is a point. Even just a free space to go test setups in a group setting is quite useful.