It sort of depended on the lounge a bit. Radiance had a small lounge, usually quiet & relaxing. Some nights though, the diamond lounge was full and it ended up as standing room only in the concierge lounge as well - with everyone fighting over the limited bar service. With more & more diamonds, then more & more D+, and now a rise in pinnacles, there is only so much space.
All the same, part of Diamond and above wasn't just about having the free drinks, but also having a dedicated space to relax as well. I feel that the middle tiers are being dudded a bit.