I disagree with this. They are fun toys. They are expensive to buy, expensive to fix, a pain to carry and move and worry about on a small boat in pounding seas, you can't have one and have your buddy swim... so it is not just one scooter you are thinking about.
One of the reasons I like freediving is the lack of BS gear to wash. Remember you have to drag it out of the garage and load into a truck- then unload from the truck, then load into boat, then unload from the boat, then load into truck, then unload from truck and wash, then drag back into the garage. Now with a scooter you have to charge the battery before and after the dive and check it as well.
I used to use the scooter for every dive when I was making money catching lobsters, it was an essential tool. I have three of them.. I haven't used one in 2 years... I am happier swimming while underwater and having less expense and hassle - not using them.
If you like playing with toys, have the money for them, do dives that leverage the significant advantages of a scooter then go for it. But not everyone will benefit from a scooter and for some it is hardly worth the trouble.