I agree with the sentiment, but it only holds true for consistent golfers. I, for example, hit my driver really well, but use mostly very old clubs and mishit a lot. I totally agree with Madcityscott; A high chance of a mishit shot due to a high 'cap means that there's no guarantee of a safe play. The modern driver is the most forgiving club in the bag in terms of engineering, but some people's swings just suit the short irons, woods, etc. better than the driver, and therefore are better with some part of their set over others.
There was a par 4 the last time I played, about 400 yards with a dogleg right and tight fairway. I hit a really solid 6 iron off the tee, got around some trees and over traps and landed about 200 from the pin, in perfect position to draw a hybrid or hit 2 short irons. It would have been great to get on in 3, but despite being in the perfect position, I mishit 2 shots in a row and proceeded to 3 putt. It didn't matter if I hit a hybrid or 2 short irons, since I bladed the crap out of the ball and got a 7. So hitting driver off the tee probably would not have mattered much. I chose to play less club off the tee because I play a slight draw with the driver, and the fairway bent the opposite way on that hole. In those cases I will generally play short.
On another hole, I hit a couple extra tee shots with my hybrid to try and reach an elevated long par 3, but I mishit it twice off the tee after playing my original ball, a somewhat successful 4 iron 15 yards short, and I ended up with 4 tee shots, one short and right, one 50 yards short and way right, and 2 hanging around the ladies' tee box. (Luckily the course wasn't crowded, or I'd have died of embarrassment.) Though my yardage with the 4i was well suited for this hole, the hybrid for me is a way higher percentage club than the long iron, so it was the safer play to hit it over the green or into the upslope than to try and land the tricky 4i on a perfect shot. In that context, the 4 was an aggressive play, since it was better to be long on this hole due to the slope.
So while many players should use better strategy and course management, I doubt it would have improved my score since few of my shots were pulled off the way I wanted. If you're a decent ball striker or can break 100 regularly, course management might help you get a lower score, but taking less club or hitting sideways out of trouble doesn't stop mishits. I think the majority of people should not bother to try and reach par 5's in 2, for sure. For some, getting on in as many as 4 should be their aim, depending on layout, etc. Most people don't think twice about pulling driver on par 5s, on principle.
But I sucked at everything except not slicing and fairways hit last time (7 or 8 proper ones with a solid shot, with 1 or 2 topped shots that made it into the fairway which I don't count). In my case, it did anything but build confidence, with the exception of hitting my driver. I dreaded being within 100 yards, and rarely hit a good shot from the fairway, but hit several good ones from fairway bunkers and trees. Hell, I hit one that was heavily topped a bit to the right, and bounced off the cart path repeatedly for around 190 yards into the first cut.
I still had fun though; that's the real way to play smart golf, after all. /rant