thanks, and seriously, if people can get away without doing mains isolation in a led lightbulb, then nobody will do it.
Mains isolation is a pain.
-Because it means using an optocoupler, with its horrendous pole frequency, which makes feedback loop control far more awkward.
basically, if someone gives you a 1 inch think block of alu and says "hold this and touch a live mains conductor with it"...you going to say "no way".........well, then they give you a few microns thick wafer of plastic and then say, "ok you can put this wafer of plastic between the alu block and the mains conductor, and then touch the mains conductor"....youre still going to say "no way"......and rightly so...just imagine, even if that wafer didn't rip, imagine the capacitive shock that you could get through it, specially if you accidentally touch when the mains has a 1kv spike on it.
The 1KV diodes you speak of don't fail, because a 1KV diode actually is built robust enough to withstand overvoltages up to a point.....but eventually, these kind of things do fail, after several years, such is the reason why line connected smps's fail.