A few days ago the HDD had its 100,000 Power_On_Hours anniversary. :) According to SMART this is way past the expected/ designed life time of the disk (the normalised value reports "1" since a few years when the disk hit about 42,000 Power_On_Hours)
So you never know. It either works or it doesn't. You have backups for the worst case.
Uptime is fine, until you restart. And poof
And especially for home use, where nien 9s is more realistic than nine 9s, you're better off having a solid backup strategy and a source of spare parts.
My main "tank" server is 16 years old this year, and has blown out one motherboard - it was a bit annoying to be "offline" for a few days as a replacement wandered in from eBay, but it worked. If it happened today I might import the zpool into another device temporarily - or permanently, who knows? This R510 probably takes more power than a datacenter.
You can get unlucky and have components fail quickly, but usually if they last, they'll last for a long time.
But trying to run a server from an SD card like in the article, seems silly. False economy, just get a good SSD.
For drive health monitoring there is SMART, but IME while it does monitor drive usage and lifetime, it rarely predicts catastrophic failure since that happens suddenly. Both drives that failed in this system went from healthy (according to SMART) to unresponsive overnight.
Hardware failures tend to follow a bathtub curve: there are more frequent failures early on due to manufacturing defects, then they become rare until you reach the end of the natural lifespan of the equipment. That is shorter for some components (spinning rust HDDs, fans, CMOS batteries, power supplies in noisy environments), but extremely long for others.
Do most people actually use them? Pretty rarely. S.M.A.R.T is just trash anyway.
But you do need to properly design your systems to limit the amount of "use". No un-needed writes to disk etc. Proper ambient detection, no point trying to rush to shut down servers when the AC pops it, and you just so happen to walk into a server room.
Some linux distribution will regularly check SMART data from disk and warn you if some threshold has passed (like number of corrected errors, spin up/down, total hours etc).
That said, if we talk about consumer hardware in a home lab or the like, of the disks that I bought in the past 15 years, only one broke down, and it did fairly quickly so my suggestion is to use redundant storage, make backup and change the disk when it breaks down. (Enterprise disk and usage is another can of worms of course).