I agree with HillRider that modern skewers are the rpoblem, but have my own theory (or explanation) why.

In all of this keep in mind that bikes were made with horizontal dropouts and QR wheels since the invention of the quick release. And up until the advent of vertical dropouts, slippage wasn't an issue. So, in keeping, with the first rule of mechanical detective work, we have to ask "what changed?".

What happened is that two things happened at about the same time, vertical dropouts, and the "CNC machined from billet" era. Suddenly we had a whole new slew of machined aluminum (except for the shaft itself) skewers. Most had external cams, but the defining feature that defined them all were the aluminum end parts, which IMO are the root of the problem.

If you've ever used pliers or a pipe wrench to turn a smooth round pipe, you'll see it in a minute. Imagine if those tools were made of soft aluminum, or simply had dull rounded teeth. Without sharp teeth capable of biting into the pipe.

So just like you want pliers with sharp hard teeth capable of biting into the pipe, you want a skewer with hard and sharp teeth capable of biting into the dropout and holding without needing outlandish pressure.