The patent on the original LEGO bricks was filed in the 50s and has long since expired. Reproducing them is not different from producing generic drugs. The innovation is in the models you design, and how well it is executed. And while production quality of the bricks is only now approaching levels comparable to LEGO, model design is an area where LEGO provides a wide opening for competitors.

I'm talking about 100% direct copies of 0-20 year old designs of e.g. studless Technic bricks.

Lepin copies the sets, including the licensed ones.

This article has a good photo illustrating what we’re talking about.

https://www.globaltimes.cn/content/1199653.shtml

The Lepin brand is out, it was "raided", with plenty of photos of said raid published by chinese news agencies to show how committed the PRC is to IPR.

But then of course other brands took their place, pretty much immediately.

Probably off the same production lines too.

As well as make their own sets, and then sell those sets for 25-30% of the price, at 95-90% of the quality.

More like 30% of the price at 60% of the quality (and that's generous).

Maybe you haven’t purchased them recently, but the quality is much higher than 60%.