[Elecraft] OT: the value of "accurate measures" for ham radio

[DOUGLAS ZWIEBEL]

For the life of me, I don't understand the apparent "need" (not just
on the Elecraft reflector) for hams who want (demand) that their ham
radio gear be so incredibly accurate (not to be confused with
precise).  Other than, "it should be able to be more accurate," how
does this impact our operations?

I don't have a Bird watt meter or 'scope.  I have an off-the-shelf
Diamond SX200 watt meter that is probably 25 years old.  Here is what
I found:

0.5 watts on the K3 = 0.7 watts on the SX200 (5 watt scale, with 0.1
"ticks" below 1 watts)
5.0 watts on the K3 = 4.9 watts on the SX200 (5 watt scale)
20 watts on the K3 = 19.5 watts on the SX200 (20 watt scale)
50 watts on the K3 = 50 watts on the SX200 (200 watt scale)
100 watts on the K3 = "just over" 90 watts on the SX200 (200 watt scale).

This looks "good enough" for me.  Of what value is more accuracy?  I
honestly can't see any for ham radio operations.  I don't know which
of my two devices is more accurate, but I don't care.  If want to run
QRP at 1 watt or 5 watts, I'm right in there.  If I am driving an
external amp, do I care what the driving power really is?  I don't
think so.  As for 100 watts vs 90 watts, I don't know which one is
right (probably neither), but so what.  The guy on the other end of
the QSO will never tell (or even measure) the difference between 90
and 100 watts.  Does any of this actually matter?

If it does matter, please let me know why...I'd really like to know!

Thanks,
de Doug KR2Q