Struggling to understand the current reserving climate on classic WOTLK

Bit of background - I am a fairly new wow classic player, started just 3 weeks before WOTLK. I used to play BC/WOTLK/Cata back in retail.I was either too young to understand, or didn’t pay attention. But I really don’t remember all the reserving being as intense as it is now.Every raid has multiple Hard Reserves, multiple Soft Reserves, 5 minute reserve windows..What happened to just raiding and rolling if you need the item?Is it a case of WOW classic players are more BiS orientated so reserving items in raids became more prevalent to ensure a more likely change of getting BiS items?I’m not against this system, just trying to understand it better.