Kettlebell workouts can be as simple or as complicated as you wish.
But remember complicated is not always best!
Don't get bogged down in thinking you need to do 10 different exercises per body part area. A good kettlebell workout with sufficient weight and decent volume will attend to many of your physical needs.
Why do kettlebells provide a great workout?
The basic kettlebell exercises - Kettlebell swing, kettlebell snatch, kettlebell clean and jerk and kettlebell turkish get up (TGU) are compound movements (multi joint exercises) which means that many muscles are used simultaneously to shift the kettlebell and also these exercises take the body through a full range of movement and also means the kettlebell travels a greater distance (compared to single joint exercises)which in turn burns more calories.
What is a simple kettlebell workout?
The most basic of kettlebell workouts would be 1 or 2 exercises
Take a kettlebell and swing it for 5 x 10 reps each side. This would equate to 100 reps and be a short but effective routine. Minimise or shorten time between sets and you'd be on your way to great fitness and enhanced explosive power (if you perform the swing with plenty of hip snap)
Another great kettlebell workout would be the previous set structure but with the kettlebell snatch.
I'm all for simplicity, check out the video below of me doing a kettlebell snatch drop set. Setting off with a 60kg kettlebell, I worked 4 reps per side from 60, 48, 40, 32, 24, 16, 8 and 6 kg kettlebells. The 8 and 6 were for fun but this truly was a very demanding kettlebell set and basis from a great workout