Each new idea has been locked in a separate piece of side content that's only relevant during the expansion in which it debuted. All of those ideas could have been infused into the main content and core systems.

By now the normal dungeons could have been doing multi path selection (variant), RNG enemy spawns and traps (deep dungeon), rare loot to appraise (deep/fieldops), duty actions such as levitate (deltascape) and even mounted sections like praetorium used to have, all of those things in the core content that's supported by roulettes and thus never lacks participation.

Using those examples, our daily expert roulette could be more than just a trash pipe speedrun. There can be roaming mobs and randomized mobs that make each run different. There can be rare tradeable loot that's worth selling. There can be duty actions specific to each dungeon to do things like break through ice walls, levitate over lava/poison, reflect certain boss attacks back.