Modifying game modes: Casual and Survival (Adventure + Hardcore)

I propose slightly modifying and diversifying the existing game modes

First, regarding Hardcore mode: upon death, the game should automatically switch to standard Survival mode (without the hardcore mechanics)—except on servers, where players would become spectators instead

This way, players who started a challenge run can continue playing in the same world—without resorting to cheats or abandoning the save—simply by switching to the standard mode

Additionally, Hardcore should be a game rule rather than a separate mode. You could enable it when creating a world; if a player dies, the rule is disabled, and the world reverts to standard Survival

I also propose adding a more difficult Survival mode.
First, the standard Survival mode should be renamed "Casual" mode, intended for average and new players

The new "Survival" mode (formerly Adventure) would incorporate Adventure-style mechanics, requiring specific tools to break certain blocks

However, in this mode, the bonus chest would be enabled by default and would always contain a wooden axe, allowing the player to harvest their first wood and begin surviving

So, the commands would be:
/gamemode creative
/gamemode spectator
/gamemode casual (formerly Survival)
/gamemode survival (formerly Adventure)

And also:
/gamerule hardcore

In Casual mode, the player can switch the difficulty to Peaceful. In Survival (formerly Adventure), the player can choose between Easy, Normal, and Hard. In Hardcore, the difficulty is locked to Hard