That's right. May be Sonic Sims should adopt that randomly generated courses too.
I think reusing the race courses for time trials would be more forgivable.
I recall before time trials, back in Sonic Speed Sim Legacy, they had separate areas for obbies. Both serving as transitions between one zone to another, to separate, more fleshed out obbies.
I think Emerald Hill had an independent obby. I don't know if I am remembering it right, but when Time Trials were introduced around Green Hill Zone, that obby was the first to have a time trial of its own.
The reason why I complain over repeating time trials in general, but think the use of obbies or the racecourses for time trials is acceptable, is because they are more specifically designed as courses to progress through than the regular time trials which are just loops around the general area.
So, like regular Sonic stages.