So, there's a debate about whether or not its necessary to let your car warm up in the winter. Some people say its entirety necessary because its bad to take off before your car's "juices have flown." On the other hand, some people agree that its a waste of time unless your car is ancient.

What's your take?

It depends what type of vehicle you drive.

For example, BMWs are suggested to drive cold. (I only know from my father.)

Newer vehicles should be fine to drive cold.

I always remote start mine in the winter though.
Older cars should be given a chance to heat up.

I don't but I'm a new driver so

I never have time since I'm always rushing especially in the morning but I think warming your car up is typically for older cars. If your car is newer it shouldn't be too much of an issue.

I have a 2013 Citroën c1. Am I doing the wrong thing by not heating it up first?

I don't know. I'm not a mechanic. LOL.
My knowledge on this particular subject is limited to local makes/models because I live in a stupid cold climate.
Google it.

oh yes we warm it up by...

Yes, for like 3-5 minutes

Depends on the car. Most cars use the heat of the engine and the engine won't really get warm if you keep it running without driving. So heating them up would be just useless and a waste of time and petrol.

by heating up you mean the cars cabin right?

I have never once let my car warm up in the winter, I don't have time for that.

This. I'm always in a rush in the mornings

We have the same car! and no, you don't need to let it warm up at all, you're good to get in and drive! (Source: My dad who works at Citroen.)

Most cold days.