I'm not conflating. Your argument sounds like you don't have any working knowledge of how the engines actually work. "Old engine = bad visuals" is not an argument. Its an opinion, a wrong one..but one nonetheless.
Architecture, data structures, rendering pipelines, those things are thousands of times more important than what year an engine fork was created.
StarEngine isn't "too old" to do what it does. It's hyper-specialized for your comparison to be remotely valid. StarEngine is a near-complete rewrite optimized specifically for things UE5 can't do out of the box or probably without a gargantuan effort of many years
Here is what Star Engine is specifically designed to do..
64-bit world coordinates for planetary-level precision
Continuous streaming of interiors, exteriors, planetary terrains
Rendering of hi-density assets across kilometers, not meters
Custom GI/atmospherics/volumetrics built from the ground up for massive scale
Server-driven visibility & replication for a truly seamless shared world
UE5 is a fantastic engine for most generic genre games, but it was not designed to handle a literal solar system, let alone 3 that we have now moving up to 5 at launch layered into a single seamless experience. That's why every UE5 demo looks so insane but exists within such a small pocket of the map. StarEngine is streaming entire planets, with cities, with ships on those planets, with players exploring all of it in the same address space. StarEngine has a different problem to solve than UE5.
StarEngine isn't "sub-par" because it's old; it's been custom built for something no other engine could do can't do. It's like saying a deep sea submarine is inferior to a sports car because the car has flashier headlights. Both are great tools, but you're comparing them without comprehending what they're individually capable of.
If engine age was all that mattered to visuals, UE5 would not have floating point precision problems:
At ludicrous scale.
When implementing world partitioning.
When firing raytraced shadows across the horizon.
When rendering real time volumetrics across an entire planet.
StarEngine has none of those problems because those things are required for it to function. That's why you can fly across an entire planet and the graphics don't suddenly drop in fidelity inside a single valley.
You're not wrong if you say UE5 is a great engine (most of the time).
You're wrong because you can't objectively apply those standards to StarEngine without acknowledging the limitations you require it to work within. You say there are better games than Star Citizen; im sure there are but they are nothing like Star Citizen. The only game that is even remotely close to Star Citizen is Star Wars Galaxies. There has been nothing like either since.