Yes and no. Long lasting guilds are chugging along like normal...the issue is lots of people came back for legion and decided they were special snowflakes and built a guild or "re-booted" their old guild.
The # of raiding guilds at the end of WoD and the beginning of Legion is quite drastic.
Now...wow has a large portion of people that will come back and quit...this time i think there was more then the past several xpac...but now there quitting again...to the point where recruiting now is getting harder than the end of WoD...not because there is less people but because people are spread out across more guilds.
Compounding this issue...the whole AP/legendary grind...has led to people feeling burnt out....add wipe 50+ of a boss...and they start to disappear.....
The key to look for a long lasting guild....then go to Warcraft logs ....how long have they been consistently raiding? What is the turn of like?
Put some thought into the decision beyond their current progression.
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Yes but poplar ones are growing....the #'s of mythic raiding guilds that transferred to Sargaras is mind boggling...especially since you can now use wow gold to get off a server.