I can definitely imagine it because Theme Park World (Sim Theme Park in the US) did this in 1999. It was one of their main selling points.

You weren't just limited to roller coasters either. You could freely walk around the park and walk into any ride all in first person.

Yeah, Theme Park 1 (1994) had pre-rendered videos to emulate riding the rides (and so for things like waterslides and rollercoasters didn't match your layout), but Theme Park World had 3D real-time rides of your layouts.

Yes? What do you imagine games looked like in 2004? That was the year Half-Life 2 came out. Obviously, a game like RCT also has to run a simulation and can’t focus on graphics as much as a shooter. I’m just saying, if anything, RCT3 looked sub-par.