>introduced abilities and natures, fleshing Pokémon out from mere collecting creatures to actual companions
>basically breathed life into competitive Pokémon
>introduced climatic variations in regions
>one of the best games in terms of shitmon:broken mon balancing, which is an actually important aspect of the game and hasn't been done as well in any game since except to some extent x/y
>introduced dive, making the water region more than the route filler it formerly was
>battle frontier (though I know fags who need full restores with pokemon 10 levels higher will deny this point validation)
>secret bases
>great region for exploration in general
>runs smooth and fast as fuck
>turned the gen 1 glitchfest into a remake that, while it could have been made more imposing, was really compromised by the original's lack of any actual action and still managed to give said game a meaningful postgame, among other things

It's strange to still see Gen 3 hate after over a decade of RSE. It had its flaws without a doubt, but apart from the villains' motives being dumb (like Galactic and the 2nd team Rocket had really epic plans lol), going a bit over the top regarding the whole legends are gods thing (that gen 4 took to unimaginable levels) and the poor level curve in general, I rarely see valid arguments put forth. I mean, nostalgiafags are incorrigible, but seeing Sinnohfetuses and younger trying to gang up on Gen 3 is just laughable, especially given Gen 4 was plotwise a rehashed Gen 3 with some edge thrown in.