Polly Esther wrote:
Well, you see, Anita, I'm not confident that this is certain -
Anita wrote If one person doesn't do a great job, your piano will not
suffer for it, so don't think you have to hit a home run the first time you
get a tuning.
My piano's had a very active life but she's not a kid anymore and I'm
concerned that a tuner could actually do some damage.
Polly

Polly, I agree, if you overtighten it can pull the whole frame
supporting the strings out of wack and there are plenty of reasonable
pianos around where it's not actually possible to get a perfect pitch of
every single note without doing damage and a good tuner knows how to get
the best out of it and also leave it such that it won't go out of tune
ridiculously fast.
Cheers
Anne