I’ve been noticing that LED bulbs keep getting worse and worse in build quality over time, but light quality and CRI seems to be getting better, but what is he absolute worst LED bulb you’ve seen?

It can be for anything, poor light quality, uneven lighting, short life, etc.

Some led lamps 15 years ago: cheap 5mm leds packed without heat management with absurd specs (like a 1.5W lamp rated as an 60W incandescent lamp).
They weren't even cheap