But spotofweather it's only a tiny proportion of children who are considered academic using 11+ criteria.
I am a professional (I'm an auditor). I didn't go to grammar school as they didn't exist where I lived. I wouldn't have got into one anyway and I was not considered to be clever at school- simply average and forgotten about. I went to uni (average/ poor) and started working and got sponsored for ACA (accounting qual) which I passed. I have a good, professional job, I earn a lot of money.
I objectively, probably at the higher end of average intelligence wise.
You don't need to be academically outstanding to be like me. You need to be a hard worker, dedicated, flexible, ambitious, maybe a bit lucky. But you don't need to be the top 15% creamed off by grammar schools and that is the case for many "good" jobs.
Do we want to go back to the 70s where teachers, doctors, accountants, lawyers, architects and surveyors all came from grammar schools and everyone else came from a comp? Why can't an average person become an (average) solicitor? A teacher? A dentist?
One thing that isn't ever addressed in this debate is that talented academics aren't needed for most things. You don't need to be a talented mathematician or linguist to have a brilliant career. Why isolate that tiny percentage to do these things when you don't need them to?