I know this is a hot button topic, but why not make a raid easy mode on the cheap:
Then adjust loot accordingly. This probably would‘t take a lot of resources to program.
It would open that content to a much larger part of the playerbase and let them train the boss mechanics which in turn will help the ‚real‘ raiders by generating a steady supply of new people who will know how bosses work without having to drag them along first.
This wouldn‘t take anything away from the current raids but add more content for the rest of the player population.