Are Electric Scooters are better for the environment ?

Yes but they charge and ride like s hit. 

In the end it all depends on how there power is created, and their relative durability. 

Your question is incomplete. Better than what?

for the work that thing can do walk, if you want to be environmental not making Electric Scooters in the first place would do it. What practical use is that thing?

Depends on what you're comparing them to.

Compared to something with a gasoline engine, yes.  The generating plant that you plug into to charge the scooter's battery produces less pollution per watt than a gas motor would.  Whatever your local utility uses as a power source.

Compared to something entirely human-powered, no.

I suppose it all depends on where the power plant is located that you are resourcing for your recharging. It's not like all electricity is produced with no negative impact on the environment.