CS1 never fully integrated expansion packs, so there were three different ways to zone the industry, and a long disorganized list of ad-hoc zoning policies. CS2 had a chance to start with more of this more coherently designed.
Plus CS2 made road editing much more precise and flexible. You can add and remove lanes instead of having separate road types for 150 different lane configurations.
I buy everything I can on GoG due to lack of DRM. If something is not on GoG, I buy from Epic simply because they pay a bigger share to developers than Steam. When I buy a game I want that money go to the devs, not middlemen.
GoG also integrates well with Epic, so I can have all my games there.