To illustrate how delightful/horrifying (delete according to taste) Dota 2's complexity is, I like to point to patch notes. Dota 2 and its monozygotic mod twin are still being balanced after a decade, with small changes coalescing into big effects on how we play the game. Have a gander at the changelog for Friday's sizeable Spring Cleaning update, which affects almost every hero and lots of items with small changes that should ultimately shake the game up for months to come.
Observe the breadth of the changes yet also how small some are, tweaking numbers by a few scant integers. Why, it's all exciting enough to make analysts chat for two and a half hours about the changelog. That's one big reason why I like Dota: it's a big weird huge horrible wonderful web of systems which work together in interesting ways.
It's probably no coincidence that this update arrives shortly before regional qualifiers begin for Valve's annual Dota 2 tournament The International. Teams will have a few weeks to start figuring out how Dota version 6.81 does and doesn't work, then we'll lead into the qualifiers with a fresh metagame. Every few months the meta shifts, with old and busted becoming the new hotness.