The problem is that all other things are no longer equal, and have not been for quite some time.
Retuning digital audio to 440Hz equal temperament is an industry norm now, even for (say) re-issued 1970s stuff. You just won't get modern digital versions that are the same as the analogue versions, and the equal temperament stuff thus won't pass a resonance test unless the test instrument is also equal temperament, which most string instruments of course are not.
The far easier test for amateurs nowadays is not to buy a whole string instrument, but to use pitch monitoring applications, which all too readily show when a sound is bang-on the specific equal temperament frequencies.
Obligatory recent Fil Henley:
Auto tune pitch correction is entirely separate from whether a properly engineered digital recording can match an analog recording to a level well beyond the ability of human biology to detect any difference in randomized, controlled, double-blinded ABX testing (https://en.wikipedia.org/wiki/ABX_test).
> The problem is that all other things are no longer equal
There are many digital recordings which have no pitch correction or other tonal manipulation applied. In those cases, all things are still equal for the purposes of the statement above.
As a separate matter, I agree auto-tune and other manipulation can be inappropriately or excessively applied, however over manipulation isn't unique to digital, it occurred in the analog era too – such as dynamic range compression and multi-band dynamic equalization. Those tools existed in tube-based, purely analog form long before digital recording became the norm and caused similar complaints when they were misapplied. There were even analog pitch correctors although they weren't nearly as flexible or precise as today's digital versions.