That's simply not true. Most cheaper coilovers have inadequate or incorrect damping for those purposes. By cheaper, I mean anything about $1k or less, just as a starting point.

I would take a car with full refreshed stock suspension including bushings, dampers, spring perch/mounts, and bumpstops over a car on bc racing or similar coilovers with no other refreshes done. If we're being realistic here, this is usually the case.

The things you're overlooking are actually some of the more important elements of suspension design. Changing the spring rate (or roll rate) is one lever you can pull to change suspension behavior, but nothing about it makes the car handle better inherently. The reason it feels that way is because the car reacts slightly quicker and has slightly less ultimate movement, that's it. A suspension with worn bushings, stiff springs, and poor dampers will ultimately have less grip than the refreshed OEM suspension.

In modern cars, bushings are designed to deflect a certain way to dynamically change toe based on how hard you corner or brake. When these bushings get worn, suspension behavior becomes unpredictable and sloppy.

The best street suspension you can put on a car is usually whatever spring rate came on the sportiest street version of your car, combined with something like a koni yellow, koni special active, or Bilstein b6/8. I personally won't even entertain any other reasonably priced shock. Then, do a full suspension refresh. That's it, OEM refreshed suspension with better damping.

I'm not going to get into how to calculate spring rate and everything, but for street use you want lower rates than the track, yet many of these coilovers come with rates that are stiffer than what many people actually run on track.