It is an oversimplification and "crappy" can mean different things at various degrees.
I expect most turnables to meet some minimum "standard". I'll go look again but it seems the old "specifications" section is now all about size , weight, power input and finish.
Often , there is no claim made regarding wow and flutter numbers. And the few I have seen are worse than what you could buy new 30 years ago! And since here we also like to throw numbers around... here is a collection of them:
https://www.vinylengine.com/turntable_forum/viewtopic.php?f=18&t=107038&start=135
Same goes for rumble.
As for arm geometry, you'd think by now "geometry" wouldn't be as much of a mystery as it were 30 years ago and it would be a "solved problem.
Regarding "fine sounding inexpensive cartridges". Yes there are. And maybe that's part of the problem.
Profit margins being what they are, the market seems to be full of pricey turntables with "fine sounding cartridges".
To confuse matters even more, add the built in phono preamp and digital output and you end up with this "thing" that plays records.
And it must be good.