I can confirm that all the flights I have been on this year we were told not to use power banks. You can have one with you (well you have to since you're not allowed to check large lithium ion batteries) but you aren't allowed to actively use it.

I've flown on half a dozen different airlines this year and all have had exactly the same stance: no power banks in checked luggage, and if they're in hand luggage you must be able to see them at all times (not in overhead storage).

You're also not allowed to use them even if you do have them with you. This is all very strictly enforced with reminders at the check-in desk and several announcements before take-off.

100 W sockets? All the flights I've been on that provided power have had a really low current USB A port that can barely keep my phone from discharging when the screen is on.