How and why:
The endless pressure to lower costs meant reducing parts counts, shrinking heatsinks, smaller fans, no fans, less this, less of that, "will it last long enough to meet the warranty" and so on. The MTBF, POH numbers plummetted or are no longer published but you now can buy 100 drives for 20 bucks in bulk.
If you are inside the warranty, use it to get a new drive.
A key factor in the life of these devices is heat. I've seen a lot of machines with CDRW and DVD drives stacked on top of each other. You eject the media and it's hot as your pizza. Simple spacing from drive to drive does wonders as well as a little airflow. Not much is needed, but zero is bad.
Why you? Luck of the draw that yours only lasted this long. Try warranty or replace it.
Your choice on the matter, but imagine how much I grimace as I watched a person I consulted face to face on that spent 2 months with lens cleaners, firmware updates (dozens I think) and the endless search for that elusive driver that would cure the drive. Sadly, they spent most of their time trying to find a cure rather than let me test-drive a new unit to see if that was it.
Best of luck,
Bob