It has been claimed that World of Warcraft is on the verge of death since the first patch was released. They are as wrong now as they were in 2004. Since 2019, wow classic has come back and become so popular.
Yes, World of Warcraft has ups and downs. I'm not particularly excited about the cataclysm (mainly because it insists on pushing Sal - Oh, wait, goel - down the throat), although I was just in Draenor's supervision before the Legion came around last month and I understood why people didn't like it. However, as Jeremy glenesk said, it is still the most popular MMO in the market, and even among people who don't play MMO, it is still the most popular MMO so far. No matter how you try to spin, these are not signs of game demise.
In most cases, buying wow gold depends on which method you choose to use when farming. People who run in dungeons all day will be disappointed. But a man who runs the dungeon all day wants to see which items in the dungeon he can sell may make a fortune.
So, to this question, I will say yes, all methods are profitable, which only depends on how much time you are willing to invest, because some methods need more time than others.