Both could definitely have used a completely updated engine at the very least (not just graphics, but scaling/capabilities around the core gameplay had grown quite a bit beyond what made sense originally), which would enable a lot of things which weren't as feasible in the original games, but it's hard to do that kind of reset and match 10 years of building and tweaking on the original. Hopefully KSA (Kitten Space Agency) can have better luck.
As far as I remember, KSP did keep pretty on top of engine updates. And I never thought the graphics were that bad, TBH. Sure, its not raytraced to hell and back, but I thought it looked just fine. However, there was a lot of physics jankery that never really got fixed (the kraken likes to eat complicated ships), and it did have performance issues in some areas. I think the community kinda wanted multiplayer and colonisation too, and the codebase was probably getting quite mangled and convoluted, making that hard. It would have been nice to see Squad get some time to be able to rework their systems over the course of a few updates, not really adding many features but focusing on performance and de-spaghettification, but I'm guessing Take-Two wouldn't see it the same way and just wanted MORE CONTENT, MORE SALES, MORE PROFIT
> As far as I remember, KSP did keep pretty on top of engine updates. And I never thought the graphics were that bad, TBH. Sure, its not raytraced to hell and back, but I thought it looked just fine. However, there was a lot of physics jankery that never really got fixed
This is what I mean by engine updates that aren't just about graphics but the scaling/capabilities around the core gameplay. Updating Unity again or adding raytracing graphics wouldn't have fixed the actual problems with the rest of the engine.
There isn't much of a business model in paying developers for a year for updates that won't generate more revenue.
If I told my boss that I wanted to spend 12 months refactoring our entire system in ways that would benefit our existing customers (who have paid once and won't ever pay again) but likely result in no additional revenue being generated, I doubt that project would be green-lit.