Tbh, I asked Hunter a long time ago why he stopped playing not long after he got his job, he said it got a bit boring once you knew how the game worked from the inside, which is perfectly viable to be honest - Chris L (or Ryan, I forget) said it wasn't very fun coming home after QAing the game and then playing it, which is also a valid point...
Ahh yeah of course, Runescape is supposed to be like a way to relax after work but if your work is Runescape, I can see how that's not really a good relaxing method
Jagex celebrated its 15th anniversary in 2015 and, with over 480 staff, Jagex stands as one of the largest independent games developers and publishers in the UK
They do have several projects such as Runescape/funorb/block 'n' load/chronicle so probably only 200~ work on Runescape and the rest work on other projects