Why Islands may fit you
Islands provides multiple activity loops rather than one linear campaign. Expeditions use puzzle and challenge rooms leading toward legendary encounters; hourly raids provide group bosses; personal dens create timed solo encounters; and ranked Singles/VGC systems use documented rules and MMR.
CobbleDex verdict: best suited to players who want constant events, custom activities and a large social network.
Ways to play
ExpeditionsTicketed dungeon-style runs with legendary or mythical goals.
Raids and densLarge group encounters plus personal timed boss challenges.
Ranked battlesNational Dex OU and VGC systems with MMR and rewards.
Realm choiceMultiple building realms including a PvP-free option.
Important caveats
The official wiki documents crates, store ranks and rank kits. That does not automatically prove pay-to-win, but anyone who wants zero monetised gameplay advantages should examine the current store before joining.
Evidence
Claims come from the official Islands wiki, including its current feature, ranked, den, raid and first-steps documentation.