I got this lamp from Nordlux, model 6315. It came with unreplacable LEDs, meaning you have to throw it away when they run out. Apparently the LEDs are rated for 30.000 hours, but will they last that long?

After a few years of normal use it died. I could hear the relay turning on and off, but there was no light. I followed the power all the way, and there seemed to be no problem with the transformer, relay or wires. I tried checking the voltage drop over a LED, and that gave a slight glow in all the other LEDs. So it seems the LEDs are connected in series! Meaning that if any of the 24 LEDs die, you have to throw away the whole lamp. I’m unsure wether this is incompetence or planned obsolescence. What are the odds of all LEDs lasting a long time?