Thundering puts a storm cloud or a tornado over everybody’s head to show which debuff they have.
I play with chat bubbles turned off and have zero problems with Thundering.
There’s no question that WoW’s UI is garbage but that’s a general issue that Blizzard continues to refuse to address. Their “UI revamp” in Dragonflight was a lot of hot air; I didn’t replace a single addon with the “new UI”.
But that’s not an issue of encounter design.
Examples?
She’s in the sky, targets a player, and strafes a beam centered on their location. Moving to the sides of the beam is safe. You don’t need an addon for this. In fact, lots of guilds (including mine) beat Raz just fine before addons were even out for the boss fight.