It irritates me that you have used your own (very unrepresentative) salary to claim teachers are well paid. Also that your posts are perpetuating myths that a) teachers moan about being underpaid, when they aren't and b) teachers aren't clever enough to do highly avoid jobs.
Most research into teacher satisfaction show that the biggest issues for teachers, and the reason they're unhappy and/or leaving the profession, is workload and student behaviour. Despite the fact that most teachers earn well below the OPs salary, it's not something that bothers teachers that much.
With respect to your view that classroom teachers chose to be 'just' a classroom teacher; are you not aware of the cuts to school budgets? Have you not seen (for a decade at least I've seen it) that staff, particularly in primary, are asked to take on responsibilities with no remuneration? Staff take on subject leads with no extra pay, no TLR, nothing but a promise it will look good for UPS or CV.
I was a stem graduate, teaching a core stem subject at secondary. I was HOD and later SLT. I earned about £50k after 20 years in my profession. Despite this being a pretty low wage compared to other stem graduates after 20 years of climbing the career ladder, it was the workload, not the salary, that led me to leave.