Let's be honest here, CrossFit is hard. It's not easy at all.
Once the whiteboard brief is done, you're moving. You go through the general warm up which a lot of non-crossfitters would joke feels like a workout itself.
You go through the specific warm up where coach challenges you in positions either in a static or dynamic way. To do this, your coach calls multiple repetitions to be able to see all the athletes movement patterns. Also during the specific warm up, you get to work on developing your skills which requires a lot of effort.
You then knock out a "teaser" before the workout to ensure you have properly scaled and to get both your mind and body ready for what is coming. Then comes the workout of the day. You push through it and get uncomfortable. Many thoughts go through your head to include quitting but you keep moving forward. You give it your best and once the workout is complete you are left on your back. You moved at a pace that pushed you outside of your comfort zone for a good amount of time.
I did not experience that when I worked out prior to CrossFit. I would spend 2 hours at the gym with my Marine buddies and we would leave feeling like we got a really good pump and that's it. During those two hours, there were some brief repetitions that challenged me but majority of the time, I was pretty damn comfortable both psychologically and physically.
We would lift and then chat. We would lift and check our phones. We would lift and watch TV.
Did we get some adaptation from our workouts? Of course we did, we were doing a workout. But did those adaptations make us fitter? No, they did not.
I am fitter at 36 years old than I was at 18 years old. The sole reason is because of the training program I do now. The dose of constantly varied functional movements executed at high intensity has increased my overall work capacity across broad time and modal domain.
I can do WAY MORE stuff now with my fitness than I could when I was 18 years old. One hour at a CrossFit gym is all I need now. That is all I need to help me kick ass when I'm in my 90's.
CrossFit is a potent program. CrossFit works.