It didn’t command the brand loyalty of the established supercar manufacturers, so it didn’t sell well. That doesn’t mean there wasn’t interest, just that there wasn’t enough to make it financially viable. That doesn’t mean that there weren’t also people with a very intense interest for such a vehicle, and that didn’t go away when they went out of production.

Honestly for the most part it’s down to individual models.

Mine has a HVAC blower that makes some noise. It’s annoying but inaudible over music. It’s a 14 year old car though (Chrysler 200) so I can’t complain too much if that’s the only issue.

More advanced variable valve timing, direct injection, better/smarter fuel and ignition controls, way better manufacturing tools and techniques, and possibly the most important, better metallurgy and base materials.