Here is why -Not truly posthuman, cyborg societies but pure form shifting is not actually a thing.  Such shifts need incremental alterations, not instant alteration as post-material entity would be capable of.  It isn’t that radical outside the virtual minds whose morphology is virtually defined and so can be anything, but even they have to still make elaborate avatar machinery to emulate their virtual forms that can often be ineffective relative to the forms of cyborgs who upgrade and engineer to realspace issues far better than the disposable android avatars of the telepresence. -Fusion/Fission propulsion mechanisms remain.  Nuclear powered spacecraft never fully went away due to the energy capacity and flux advantages they have.  Fusion is a stable generator of energy, but it lacks the kind of high energy capacities of nuclear (with antimatter propulsion being a more extreme version of nuclear in terms of dynamics while chemical rocketry is even with the advanced synthetic fluids of [[Prospect Space]] biotechnology a backup fuel mechanism).  Blackhole propulsion is a hard sell for even the Architects, as the gravity manipulation and containment fields needed just isn’t there.  -The antimatter plateau, Antimatter weaponry acts as a near-plateau on hard capabilities for missile and particle beam technology until one manages to crack energy-mass along with gravity manipulation mechanisms, things the Architects and the Sprawl managed but not Prospect Spacers, [[Phidians]], Plexus or [[Tikali]].  Even than, Architect technology still can be harmed with antimatter technology it is just they have ways to divert, deflect and evade it that are far better. -FTL is slow.  Even with hyperspace construction, trips are long and warp travel is slow.  Long expeditions, Cycler routes and dense clusters of civilization are the norm as a result.  Even with the Sprawl, a wormhole trip can be decades in real time if not cause more weird CTC oriented issues. -AGI horizon (scaling of AI has the ‘complexity wall’ where the computational power yields less effective results when trying to go for ASI, ASI gods cannot happen and even advanced ASI that does exist is very reliant on a vast webwork of co-mingling agents that it offloads its work to.  Very marathon inspired in a way). -Mind Uploading tech is… mixed.  The population of the Plexus is not the product of mind uploading being perfect, it is far from it.  Instead it is because of aggregation of uploaded minds over four centuries, with the 2500’s Plexus being not even the actual modern plexus but a disoriented meshwork of different virtual polities that had to be connected in such way that converged onto the Plexus as a binding force some did see as the next try at a unified humanity despite the huge problem that was how the dominant societies are the Assembly and VC, whose fundamental conflict bled into the Plexus so much the Plexus had to create AGI to act as arbitrators of Plexus neutrality as a property of the Plexus.  Something the Plexus managed to get in place 160 years ago through how much leverage their processing power, data archives and control of important server infrastructure gave for pressuring the Assembly and VC into a neutrality pact on Plexus matters.  The self-interest of the Assembly and VC also gave a way to get them to go along with the Plexus neutrality as if the Plexus did side with either faction the subterfuge and warfare actions of either power would have led to (in a total war) many servers getting hammered with mass driver. #StreamOfThought #MetaDisputed #technology