The level of knowledge and competency in maths/physics/chemistry...

The level of knowledge and competency in maths/physics/chemistry is definitely lacking and is nowhere near as high as it was in the 70s/80s/90s. Good teachers are worth their weight in gold. However maths/physics/chemistry in high schools has been severely degraded. I have run into multiple high school physics teachers who have not studied physics and maths beyond high school and who simply have a poor level of understanding of their subject despite 'teaching' it for years. I also know of some very good maths/physics teachers in both fields who refused to teach under the new maths/physics curriculum. They moved from teaching in high schools to fixing the problem the education system has created, and now work outside of the high schools for Unis and as private tutors.