In general I agree that compound movements are the best, but in my personal experience most people have postural weaknesses and habitual movement patterns that they just might not be aware of that even compound movements have a hard time addressing. When you start exercising your body may overcompensate for these weaknesses by recruiting muscles that might be less than ideal for the movement, which can lead to injury (which happened in my case).
For me personally, one of those postural imbalances turned into an injury (shoulder), and I found doing exercises that targeted a very specific muscle (infraspinatus) really helped in my recovery.
I think everyone could benefit from spending some time exploring their body by targeting muscles that may be easy to ignore in larger compound movements, if only for bringing awareness to them (which should benefit the main movements in the long run by making them more efficient).