That’s essentially what happened—remember when cellphones were still getting popular and you could only use the specific charger provided at the time of cell phone purchase? Someone actually succeeded and got companies to agree to micro-usb and lightning chargers.
As for not cellphones... it’s a WIP
having a universal thing for all of a specific category of thing is a bad idea. Youll have things getting too much or to little because they run off of different amounts. The too little isnt as much of a problem as too much in that too much can ruin your kit. If everything used the universal thing then youd have a commonplace problem of people borrowing someone elses power cable/charger and frying their stuff.
As for not cellphones... it’s a WIP