UNIT - Creature Balance + Visual Changes

I agree with Frozensoull – it's a personal matter for everyone. If someone, as described, learned the old manual, and then the entire game was suddenly changed, no one is forcing them to use a particular mod or play only with it, refusing to play the original. People develop mods for various reasons: because they want to, they want to discuss it with others who are also interested, especially if they agree on a particular issue. This turns the game into something that can not only be played but also modified, discussed, and new versions can be tested, and decisions can be made on how to proceed in a particular matter, rather than simply playing with a limited number of maps, having a limited choice of characters to play as, and a limited number of game tactics. All of this generates dozens of debates and, as a result, keeps the game alive, rather than gathering dust on a shelf or in the deepest folder on a computer.

Added 4 minutes later
Of course, I don't deny that every modder would like their mod to be popular, but even realizing that this may not be the case, people continue to do it, which means that this is not the primary reason