Suburb doesn't mean car constrained. I grew up in the suburbs and rode my bike and skateboard just about everywhere from the time I was 13 to the time I could drive.
Commercial zones that have groceries, restaurants, shops, and entertainment are almost always several kilometers away. You could technically bike there, but there are rarely bike lanes. And due to serving the needs of a large, low-density area, you’d have to bike on multi-lane high-speed thoroughfares which is far less safe than being able to use small local streets. Where there are sidewalks, they often end abruptly and don’t actually connect to anywhere or anything.
It is truly hell.
My (American) definition of suburbia primarily involves a lack of sidewalks.
Go play SimCity again. The concept of mixed-use doesn't exist because it's built by an American.