How can you consider gear from vendor back in TBC catch up when it took about 10 000% more time and effort than now? Like what is this? There is vendor with couple of items at power level of t5 = catch up? So you telling me that vendor what force you to do dungeons and old raids like Karazhan is catch up? I would rather say it is simple vendor what rewards you for doing content and nothing els.
Catch up is something like when you join game you get instaly geared for upocoming new content which is something what wasnt happening in ¨TBC. You bought 1 or 2 items top if you played casualy after farming weeks in heroic dungeons and Karazhan thats hardly catch up. Compare this to afk warfronts, or afk LFR, or hero raid items raining on you doing world quest.
And people were not careing that much becouse raids were still exclusive with no difficulty levels. Boss kills had actual value. You could get geared as much as you want from vendor it would not change fact you still have T5 or T6 to clear. Than Blizzard made raids accessible. So only thing what was exclusive about doing challengin heroic raids was gear. Now they removed exclusivity even from gear to let everyone one catch up and get geared doing trivial or easyer cointent like mythic+. At this point they could also just remove raiding on top of making all effort and time investment completly devalued by bumping up itemlvls from all sources.