I generally wouldn't suggest giving any weight to the claims of driver updater/scanners. It's in their interest to convince you drivers need updating, for a fee. If a driver does need to be updated, almost without exception one can be sourced from the device manufacturer without cost.
However in my experience, video drivers are the most likely to benefit from updating, but then really only if a problem occurs, or if a version release provides a benefit like performance enhancement especially with specific games, or bug fixes that affect you. Otherwise, unless a driver has a bug, the hardware hasn't changed so the operational requirement of the driver also hasn't changed. In fact for older systems, the final stable driver release for a device can be years old, maybe even older than the computer. Driver scanners may either simply say drivers are out of date if they are dated more than a fixed timespan in the past, or if there is any driver available from a later date, which may be a beta release, not WHQL certified, not necessarily ideal for your computer etc.
If a system is becoming sluggish, it can be due to age issues like the hard drive beginning to throw errors, but it can also just be greater demands being placed on a system of limited capability, or some maintenance tasks not attended to. There is also the possibility of malware.
As a starting point there is a useful topic here: