>>52196134It was already explained to you by another anon, but to rephrase it, it was to introduce variance and give personality to what otherwise are just sets of data. It gives the creatures some flavor beyond their visual designs and dex entries, to give a kid not just a tool to battle with, but a friend to love. This is what the franchise was created for, and you can look at the handful of interviews Taijiri has given for proof of it. You can argue about whether the games, especially the early ones, succeeded in this goal, but it's very clear that this was the intention.
It wasn't until older players, unwilling to just let a game be a game, took the games more seriously and start demanding more avenues for competitive play, as if these games were fucking e-sports, that things like natures and IVs became more transparent as mechanics.
