There were about a dozen of us guys planting brush in those days on that lake. . Sometimes we would plan to brush up a spot and find out some one already did it. Most of mine were in more obscure places. I was single and didn't hunt then so it was a good use of my time.
In lakes with little deep water cover, or cleared parts of a lake,..it does help.
With the electronics, GPS, Side scanning, etc......time spent idling around can do almost as good as planting brush. A tiny tree, stump, or rockpile that can hold a few fish is as good as a monster pile. The key is to be able to locate it quickly and get a bait in there.
The last time I bass fished there , my buddy and I hit a few of them just to see if they decayed or still held fish. The lake was low, no current , late August and not a cloud in the sky. The first couple held nothing but we caught 5 that weighed 14-15 pounds off the last one we hit. Two decent sized events were held that day and 12 won both of them. Chances are no one had hit that spot in years.
Many crappie guides do that as well,..Some lake like Lake of the Ozarks and Table Rock , there is enough planted brush to just look for it instead of planting.