On this thread it is definitely crass, and to be honest just stinks of sour grapes. Privilege is something to be acknowledged, understood and challenged, but when you can only build yourself/your DC up by bringing others down then that’s super unhealthy.
There are many types of privilege too - not just private school. I’m in NI where private schools aren’t really a thing, but we do have a very successful grammar school system across the country, and voluntary grammars in particular are better equipped than some other schools in the country. (Not private - just slightly differently funded - my fees for my DC to attend a voluntary grammar are approx £400 per year per child so not even close to private school) The class sizes tend to be smaller though and there isn’t the same range of ability for the teachers to cover as in a fully comprehensive system.
On the other hand, we’ve had some shit teachers over the years, and there is a real shortage of subject specialists in some subjects and that has affected my DC as much as pupils in non-selective schools. My eldest had 4 different teachers for GCSE Spanish for instance over the 2 years and a 2month period with cover teachers who were not subject specialists.
I do acknowledge that they are privileged to attend/have attended the schools they have however.
My DD achieved 2 Astar and 1 A at A level, as well as an additional B at AS level. You could look at her and think she only achieved those grades because she’s at a grammar school with smaller class sizes and other privileges, so her grades aren’t as valuable as the same grades from someone from a non-selective school. (which is effectively what’s been said upthread)
But what you would miss is that she also skipped a year group because of when we moved back to the UK, so skipped 2nd form altogether, had a mental breakdown during U6th, was diagnosed with ADHD in her first year of uni (with all the evidence of that really playing out during her A-levels), has continuing trauma from my cancer diagnosis when she was just starting secondary school and dealt with watching her beloved granda change to a completely different person over the last few years as Alzheimer’s has taken him away from us repeatedly.
It’s lazy and frankly disgusting to diminish the achievements of any of our young people - you have no clue what they’ve been through, and to suggest that an Astar from a comprehensive pupil is somehow worth more than one from a private/grammar/middle class/privileged (delete as appropriate) pupil is a disgrace.