OK, understood. I used my ER2SE's in the gym today. The isolation's pretty good. I've used ER4S, ER4P, and now ER2SE's in the gym for around 20 years. I even use them around the house and to watch movies. I have Bose Quietcomfort 20's, I use them for napping without plugging them into anything. They kill neighborhood ambient sounds pretty well. I don't think my Sony WF-1000XM3's do as well. Not sure how much I'm going to use them. They sound great, no question, music sounds wonderful, but the noise cancellation is nothing to write home about.
No wife and kids here, so isolation of the Etymotics is great for me... almost anywhere. Trains too, of course, but I only ride one once in a while.