May one use an escalator on shabbos?

People are still going on about this? I thought it was settled.

RoB: You usually can rely on Avi as an ally when you’re arguing with the religious right; when even he disagreed with you, it was time to pack up and move on. It was NOT time to accuse him of “siding with the machmirim” as though it’s some kind of vice. Saying it’s mutar to ride trains and buses on Shabbos is like saying it’s mutar to flick on and off LED lights. You can make the argument, but you and everyone else here knows that it’s rejected by–I think we can pretty much say–everyone. If you were using the bus and train argument to show DY that buses and trains are not comparable to escalators, I would say you are a brilliant debater. But, you fell into your own straw-man and starting actually defending taking a bus to shul.

As for the doctor, didn’t the Rambam say it’s preferable NOT to use a Shabbos goy in cases of pikuach nefesh? (If that’s not mainstream let me know. I don’t want to join the ranks of people to argue with Rambam poseks that nobody holds by).