We didn't even have proper harnesses 3 years ago. Claude Code which more or less kicked everything off is under 2 years old, before that you would've had to use Cursor or something. And we now have local models better than the frontier ones of 3 years ago if you have a good graphics card or an SoC with lots of shared memory. The cheapo Chinese models now beat the super expensive American ones from just a few months ago.

Whole thing is changing so fast if you haven't tried it in a few months, you don't really know what it entails now.