Where did tracking error go?

Back in the dark ages, when men were men and I still owned vinyl......
There were many tonearm designs, not to mention linear tracking designs that were meant to keep the stylus perfectly in the track as the tonearm moved in an arc across the record.
My local dealer carries a few fancy schmancy turntables - but none of the tonearms address this. He couldn't answer the tracking error question - in fact he looked like he hadn't heard of it before.
How did we make this go away? What's next - gravity?