Excellent article which sheds light on the potential negatives involved with upgrading an SSD, whether installed by your good self or at the instruction of salesmen riding the diminishing SSD wave.
Vague statements like this one confirm my OP.
An SSD being fitted will not repair, for example, a laptop's glitchy monitor, faulty keyboard, or failing motherboard.
Beware of any advice promoting an SSD upgrade as a magic-pill to improve your computer's performance as If you're dropping any fresh component into the system that asks for more power than the original parts the machine's power and cooling solutions were designed for, then you're liable to make a loss in battery life and gain a chunk in heat.