So why hasn’t it been done?
OK, you’re at the hotel and your phone/tablet needs charging but you’ve to be elsewhere right now. A situation common enough. Do you a) take the phone with you and hope the battery lasts? or b) put it on charge in the room – and hope no-one steals it while you’re out?
Most hotels provide in-room safes so that valuables can be left securely, yet it’s hardly secure to leave an expensive phone/tablet charging on a table. Should it get stolen the first thing the hotel would say is “Why wasn’t it in the safe?”
The solution seems, to me at least, very obvious. It’s hardly a mammoth task to install an electrical socket (& vent) into the safe.
Any hotel that did provide such a facility would have a USP to encourage guests and would almost certainly quickly recoup any costs through increased visitor numbers. I know that, personally, given the choice between a hotel with the facility to securely charge my phone and one without, I’d pick the “with” every time.
So why isn’t it available?
May I suggest readers do as I’ve done and request each hotel that they visit installs such a facility. With enough requests commonsense might just prevail.