Lifespan of LEDS Ethereals

I own a set of Maxspect Ethereals ( 3 of them on my tank ). They have been great lights with very few problems.
I was speaking with another reef hobbiest who mentioned that even LEDs have a life cycle and at some point the light intensity begins to reduce.

I’ve had my Maxspect Ethereals since 2017 and I guess my question is how long should I expect my LEDs to last? Are there any signs that I can observe to help me understand whether my lights are aging, etc.? At this point, all the LEDs work- nothing has burnt out, etc., I’m just wondering what to expect and observe from a lifespan perspective.

Final questions
Are Ethereals still being sold? They are on the Maxspect website but making sure that it’s still a valid, current product.
What is the latest firmware for Ethereals? Just want to make sure I’m current.