Cloudinary is a nice tool however it does not automatically size the image or compress images, you do using the API. Which is very easy.
Most of my images there are +4000 pixels wide at 150 dpi with zero compression. I don’t embed source images, I create derivatives with the api and use this tool as a digital asset manager.
Using the tool as an image generator with webflow make it very easy to create images for your particular design and then download and upload into webflow or generate and paste the image into a rich Textfield.
It would be AMAZING to be able to use cloudinary sources right in the designer without custom embeds. One can hope.
To reiterate what @dram is saying; you need to determine, as an art director would, the dimensions, crop, resolution, and compression of the “source” image you upload to webflow. That choice is going to cascade down into your design. Too many designers here just throw some large image to webflow, and think manipulation of the dimensions in css will magically optimize the image in the browser. Especially with background images , WHICH ARE NOT OPTIMIZED.
The #1 issue people complain about when doing page speed tests, is image load. Yet that is all on them.