Why is SMART HDD bad?

Question

Hard disks

Why does CrystalDiskInfo 8.0.0 show an alarm? And why is the Unstable Sectors attribute highlighted in yellow? After all, the worst value of this attribute never fell below the maximum. Help, plz, decipher the situation.
PS. HDD without load heats up to 45 degrees. and "colloshmatit" to the fullest. It is clear that something is wrong with him, but the main thing for me is to understand the conclusion of SMART

Answer 1

It will be more clear if you look using hdd.by/victoria
Decryption of Smart parameters
https://www.ixbt.com/storage/hdd-smart-testing.shtml

Answer 2

C5 is Current Pending Sector Count. The hard drive hit a sector that it couldn't read. Further, depending on the firmware algorithms, it can both wait to try to read the sector again, and then remap it, and, if it is possible to write data to this sector later, remove it from pendings.
The warning is reasonable, but I would still translate it as "warning" and not "alarm".
You can additionally check the disk with R.tester: https://rlab.ru/tools/rtester.html
It has many more testing options - both reading / writing with detailed graphs, and status diagnostics based on built-in algorithms.