When do you use a rasterized layer in photoshop?

It just came in to my head. Aside from letting you do some filter, when do you rasterize a layer in photoshop?

 

if you rasterize the layer only the text or shape content is rasterized. Rasterizing is a good thing if you are already done adding the effects and filters. Because if you rasterize then add the filter, it will only get applied to the text or shape and not the effect.

 

In theory, you should try to avoid rasterizing shape layers (if possible). It's not the end of the world if you do, but remember that you'll never be able to scale up your image without loss of quality after that.

 

I always rasterize but I always start with bigger resolutions. Let's say if I need something in 500x500 I'll start with 1000x1000 and then resize at the end...

 

I want to know why do you rasterize your layers? is it something like saving file size etc?

 

I would only rasterize a layer if I need to work on it, otherwise leave it as is.