CS 1.6 was peak gaming. There were servers with Warcraft 3 mod where you could pick your race and level up to receive additional modded abilities and items, and it would save your progress over months. Not to mention the map customizations.

Also, no paying for season passes or DLC, no paid skinpacks, no censorship or embedded ads or tracking. And custom porn sprays.

EDIT: there were definitely skins, they were just free downloads from modders. And they were client side so you could see them but other players would just have their own skin or default for the same item.