Originally Posted by
Marrilaife
That's the reason Blizzard made normal & hc scale between 10 and 30 players, so guilds that run an average roster of 15-20 people can afford to take a few more during times of high traffic and can still raid even if a few doesn't make it. If you're raiding on a bare minimum 10 man roster then yeah, it's a problem (also some bosses scale unfavourably for the low-end size).
Also that's the reason personal loot was implemented, skips all the loot drama and no more "we pumped gear into this guy and he left", because there's no pumping anymore just individual luck.
Mythic raiding still operates with mostly old system, static lockout, fixed size, often loot master system, but normal / hc is very casual friendly these days in a way it's lenient on people who can't upkeep stellar attendance due to rl commitments or other reasons.