We would have a problem with something like IO throughput on database instances. We would open a ticket, wait a little while, get a response. If we claimed it was hardware related (because we couldn't tell from our host's perspective) we got the response "it's not the hardware, everything seems fine." This would go on for days. Then eventually, after we had to prove the numbers were erratic or unresponsive we would eventually get a more helpful response. Maybe.
It's a very cold splash of water in the face when you realize that your hosting company, cloud provider, whatever is not in business to hold your hand. If you need more than their minimum level of support or require human interaction you will be sadly disappointed. These companies maintain their margins by automating hardware provisioning, homogenizing infrastructure, and making it as turn-key as possible. Which is all fine and good until you need something their infrastructure doesn't provide for. Like switch bandwidth. Like larger instances. Like all your VMs in a local rack.
You will have hardware problems in the cloud too and they will not be obvious. You will need the same degree of monitoring software you have anywhere else in any other environment.