One problem is that the word "piano technique" is poorly defined. A good technique includes A) playing all or, say, 99% of the notes correctly, with correct dynamics, and tremendous speed if necessary. But a technique becomes really impressive if B) difficult passages are being mastered in an ingenious, original way, with effects that one usually believes to be impossible to produce either at that speed or in a general way; and in a way that totally matches the spirit of the music. For some reason excelling in one rarely goes together with excelling in the other.
In the older generation there were very few from the A-type but lots from the B-type; today it is the opposite. When I say this, I exclusively refer to piano technique, NOT to musicality.
Rubinstein, Horowitz, Edwin and Annie Fischer, Kempff, Haskil, Cortot had wrong notes all over the place (see Leonskaya, Perahia, Uchida, Brendel for more recent examples ...) but they got out incredible technical effects from the piano on the level of sounds, colors, dynamics (e.g a magically delicate prestissimo run of sixths starting in p and finishing ppp). I mean, these guys were real artists of piano technique and not merely reliable super-technicians. This is one of the reasons why many listeners still prefer Cortot's Chopin Etudes to those by Pollini, Lugansky, Beresowsky, even though there is rarely a sequence of more than 10 sec in Cortot's recording without some very audible wrong note.
There are a few legendary exceptions that had both skills e.g. Richter, Michelangeli, Pletnev (sorry have to include Pletnev in past tense, imo as a pianist he was better 10-20 years ago).
Today, we have A-Types all over the place. What for?
Topic: Which professional pianist has the worsest technique?