Anno 1800 has a fantastic co-op mode where two players build one empire together. The repack cannot access Ubisoft servers. You are locked to single-player only. No coop with friends. No multiplayer naval battles. No sharing blueprints online.
Deep into an Anno 1800 save (10+ hours with 50,000 investors), the legitimate game handles memory fine. Repacks often have memory leaks because the crack interferes with the Denuvo hooks. Many users report that their repack save becomes unplayable at Tier 5 because the game crashes every 15 minutes.
Anno 1800 is a "forever game." It is designed to be played for years. The repack cuts you off from the living community, the modding scene, and the critical stability patches that make the endgame enjoyable. You will spend 10 hours building a beautiful steam-powered empire, only for the cracked version to crash and corrupt your save.