The article does not even mention long range attacks in which large portions of the block chain are rewritten.

This is made extremely hard in Bitcoin through proof-of-work. To rewrite history you must re-do all of the work, which means you burn enough real-world energy to work faster than the entire rest of the network (aka majority hash rate attack). It's allowed, but expensive.

In PoS, there was never any work, so you can just rewrite history.

Every time the subject of Ethereum's move to PoS comes up, it seems this issue is there. The solutions mutate into a head-spinning kaleidoscope of different guises, all rabbit holes in their own maddening way and suspicious on that basis alone.

That this lengthy piece doesn't even mention long range attacks speaks volumes.