Bicycles aren’t just “fun”

People use then to get places. Like to get to work, to make deliveries, to pickup kids from school, etc.

Where did I suggest otherwise? I commute over 200km’s a week on a bicycle myself.

You need to plan for people traveling on bicycles at traveling speeds. And that includes signage and traffic lights so that cyclists don’t have to brake at every intersection.

What difference does it make braking for lighting or signage that orders you to do so, or an unmarked intersection?

Accelerating with a cargo bicycle full of groceries every block is a huge decrease to efficiency

I do weekly groceries on an unassisted cargo bike and this really just isn’t a real problem. The stopping an starting.