The quality of education is improving.
I know you're being semi-sarcastic, but I suspect it probably is improving.
My secondary school teachers where a mix of old-school amateurs with no formal training in education, and college of education graduates. Those with formal training in education were at least OK teachers, some were great, but only one of that group was terrible (He disliked children and I'm pretty sure he signed up only for the long holidays). Some of the older 'amateurs' were good teachers, some were so bad at their jobs that in any other occupation, like road sweeping, they would have been given the sack long ago.
At least nowadays teachers will all have some formal teaching qualifications rather than starting from a non-education degree (or less) and winging it.
While the science of education has matured, and the quality of the teachers has improved, and hopefully continues to improve, over time, not all is necessarily improving. In the areas I'm best placed to judge the 'level' of what is being taught nowadays compared to what was taught in my day - basically science and mathematics - I think I do see some 'dumbing down'. I think it is politically motivated, so that successive governments can claim that there are better national exam results now than were delivered under their predecessors.
What damages education is when, as it has in the UK, it becomes a political football. I don't think any generation since mine has made it from one end of their education to the other without some major upheaval in how education in the UK is organised. Politicians get involved and educators get ignored. I looked through the national curriculum a few years back and it was remarkably clear, from the ways certain 'learning goals' were worded, that political goals had become embedded in the system by the government. Parts almost read like a 'New Labour' manifesto. In my day there was no national curriculum, so tampering with the level or content of curricula was not possible in the same way as it is now, with effectively direct government control of the syllabus.