It has been this way since WoTLK. So… you are referring to Vanilla and TBC. Which you could not choose what raids you wanted to do. You had to gear from one tier to get to the next. Which meant by end of expansion, if you started late, you were going to have a hard time seeing the final raid.
Additionally, you would have guilds poaching players. Meaning, The better players in guilds, would leave for a faster progressing guild. Which meant you had a lot of feeder guilds that got stuck at a progression point, because they kept having to gear new players to progress the content they were on.
We still get a raid per patch. Same as then. But, we dont have to run the previous patch raid to be able to do it.
This is a 20 year old game. The type of content cadence you want would require close to doubling the team size. The main question is, would they be able to increase the revenue of the game to compensate? I can confidently say, that they have most likely done a ton of ROI analysis on that very question. And the development we get, is based on that.
It is largely how the modern gaming industry is run. Very few passion projects. Investors want short term quarterly gains. They want to invest in what they feel are “safe” investments. Then want to see large returns. And its tough to pitch that investing a ton of money into a 20 year old game is worth it.
With the recent large scale failures such as Suicide Squad Kills the Justice League, Skull and Bones, Concord, Dustborn, Forespoken, we are seeing what the gaming industry is becoming. With buggy game launches, and games launching that are feature incomplete, and take a year of patches to actually be the game consumers paid for, we are seeing the direct result of what the gaming industry is becoming.
It is a lot of passionate game developers, who are under the thumb of a large company, who decides what is made and when it launches, governed by a board of directors who represent the investors. They do not care are all about what they make and what they release. They just want good returns. And all of the recent flops, and utter garbage coming out of AAA studios truly shows how out of touch they are.