6 yr old with a dummy

[Stinkydad]

my 6 yr old still used a dummy ,and it drives me up the wall :(
mummy says he will grow out of it in his own time,
how can i persuade her ( considaring she is one of the most awkward person i have ever met ) to be on my side without causing an argumnet again
should i just leave it and give in or should i put my foot down and throw them all out in the bin ( she will just go out and buy some new ones anyway ?

any advise please

Most dummies are orthodontically approved so I understand teeth malformation is less of an issue than it used to be. Thumb sucking is far more detrimental to growing teeth.

My friend's little girl still had a tatty old muslin (her form of soothing) until she was 8, but it was only at bedtime. And my DD who is 3.5 still has her dummies at bedtime. I'm not fussed about her giving them up as she still derives a lot of comfort from them.