One thing I always wished Warcraft 3 did was actually use the hero stats (agility, strength, and intelligence) in the hero’s abilities. Each level of an ability should increase the damage/healing a spell does based on the percentage of one of the stats, not just a flat number that will never change once the ability is at level 3. This would also make collecting stat tomes more important. Just my two cents. I’ve never looked into if it would be possible to modify all the existing spells to use the stats or not. I just figured it’s not possible, at least not without a TON of coding to redo all the abilities from scratch.
Given tomes are often random and there’s no real mechanism to try and raise an individual stat, I don’t think the added complexity provides much benefit.
If you had some control of stat increases during levelup (maybe you can put X points into any attribute, but you get say double for your primary attribute) then it might be worthwhile. But it would be quite complicated (and IMHO a bit annoying) to have to do that during a melee game.
There’s a lot of suggestions/requests to allow triggers to manipulate spell properties during gameplay, which would make scripting this a lot easier - but you’d still need to script it.