Generally because you’re buying cheaper ones that aren’t built as well. Heat destroys LEDs and the cheap bulbs generally use fewer individual LEDs running at higher power to produce a given output in lumens. More expensive bulbs use more LEDs at lower power to achieve the same light output so that they’re not constantly being overdriven and last much longer.

What would you recommend?

I have dozens of Philips Hue bulbs 6-10 years old and I honestly don’t think one of them has died. I’m sure they have lost some luminance over time, but they still get the job done no problem. I rarely run them at 100% anyway.