We tried to use Azure for a new system ~8 months ago (it's hard to pass up that much money). Spinning up a vm with the image we needed and a static ip was not possible with the GUI. The specific image we needed was only accessible on the "new" portal, but a static IP could only be assigned from the "old" portal. It's theoretically possible to set it up with PowerShell, but after spending over a week of poring over outdated and incomplete documentation and opening support tickets, we switched to AWS and had it running in a few hours.

Even if we did get it to work, I'm not sure I would feel comfortable investing in a platform where something as simple as "create a vm with this image and assign a static ip" isn't straightforward. It could be better now, but for us (and most other young startups) the time of our engineers is much more scarce than hosting costs.