How much do you pay for those LED T8s?
With incandescent type LED replacement (probably true for T8) I have seen LED bulbs add the spec for on/off cycle times.
For home use, this would make the bulb life much less than the LED life itself!
Anyways ,
the 50,000 number is for the LEDs only, not the bulb.
Here is a E27 example specified at 11,000 hours by philips.
Thus they claim 10 years at 3hours/day.
Is this a reasonable calculation?
I think not,some bulbs are used much more a day,up to 3 times more.
So ,3 years would be a more realistic number.
Note that you can get bulbs with 3 years warranty! and some do replace them no questions asked
I tried 2 2000 lumens(E27) bulbs.
One poped after a few times of on/off (and replaced no questions asked),
the other works fine for about 6 months very bright warm white light.