Squatting before the Olympic lifts I think gets hated on a bit too much in the Olympic lifting community. That, or I am just talking to the wrong people. I think squatting before doing the competition lifts or variations of can be quite useful for some people.
First, it allows you to push the squats harder because you simply have more energy in the tank. The downside of this would be that your Olympic lifts may suffer because you have less energy in the tank. However, I think this can be mitigated if you pick the right variations of the Olympic lifts.
If you try to do all your lifts from the floor after squatting you may be in for a bit of trouble as that is more taxing than say a snatch or clean from blocks. So, if you are going to squat before your Olympic lifts it is best to pick variations of the lifts that aren't as taxing as your typical competition lifts. Things like blocks, powers, hangs, etc. might be a better bet.
Secondly, speaking from a purely theoretical standpoint I think squatting first can provide some unique adaptations. Obviously if you're squatting heavy before anything else your force production is going to drop off. But, I think this provides an opportunity to recruit motor units that might usually go un-recruited because you are much more fatigued and your body essentially has to find ways to keep producing more force. Trying to produce a lot of fore when you are fatigued can go badly if you take it too far, but there is probably a middle ground when you are tired and still getting quality adaptation by recruiting motor unit that are usually untapped when not as fatigued from squatting. The idea would be that those units become primary after adaptation and you can produce more force.
Lastly, squatting first lets you shut your brain off during the lifts because you are simply too tired to overthink technique or have anxiety about a specific attempt.
Fatigue an be a good thing to tap into so don't shy away from it. I think there is a productive way to add squatting first to a program if you understand the effects of specific load/volume of various exercises. And remember, this is something you would only do two, MAYBE three times/week during a training block.