What do you mean small cars have never handled well? Honda built their entire brand on small, affordable, reliable, well handling cars. Small cars have less mass to get in the way of good handling. What mass small cars do have is lower to the ground, which improves handling. Unlike large American vehicles, small cars have innovative features, like independent suspension. That improves handling.

I agree with most of your points except this.

Innovative features like independent suspension? Almost every single sedan or crossover since the 90s has been equipped with fully independent suspension. This isn’t the least bit unique to small cars or foreign vehicles. Even many large American SUVs like the Expedition and Tahoe have IRS these days. The one common exception, besides pickups and off road focused SUVs that need solid axles for practical reasons, is small cars. Many small economy cars have torsion beam rear suspension which is generally bad for ride and handling but lightweight and cheap.

You are right that it’s easier to make smaller and lighter cars handle well, most of my vehicles have been light sports cars like the Miata. However, damper design, suspension geometry, weight distribution and chassis design are every bit as important. Cheap econoboxes often suffer in this regard.

You can make a tall and heavy vehicle handle remarkably well. See sporty SUVs like the Porsche Macan. The Honda Performance Development team has road raced minivans and mid size SUVs, and they are quite quick.

On the other hand, you can make a small vehicle handle like absolute garbage. The issue with very small family cars is they often tend to be cheap and sacrifices must be made to hit a price point. Many of the lightweight econo cars I have driven have handling as bad as my lifted, solid axle, 5000 lb Land Cruiser. This includes the base Toyota Yaris, Fiat Aygo, Suzuki Jimny, and Dacia Duster to name a few.