The old and good times were not so good if you had to defrag your hard drive. That task of maintenance that allowed to optimize the behavior of the disc became a whole reef for some companies.
In fact, an entire industry emerged around the defragmentation, but the arrival of new operating systems, better file systems and especially SSD units changed the landscape. Not so much, however: it turns out that the defragmentation was not dead, but that it was partying.