Very much so. I personally use 15 FPS all the time. On mobile the change is minimal/barely noticeable in terms of performance for the usual things you're doing (like fishing or afk slayer) and the battery drain is a nice chunk less!
This thread was added on March 13, 2019, with posts from Jagex_Wolf.
Original Post
https://i.redd.it/dpab0oms2vl21.jpg
you dont notice difference between 60fps and 15fps?
for the usual things you're doing (like fishing or afk slayer)
I'm not really paying attention when I use mobile personally; I definitely think it'd be noticeable doing something more intensive for sure :P
Maybe I should have worded that better, sorry! :)