On-premises servers have a predictable lifecycle. They age, they get harder to support, and the cost of keeping them running climbs every year. Licences lapse. Hardware fails at the worst time. Patching falls behind. What was once solid infrastructure quietly turns into a liability, and the longer it runs the more disruptive the eventual move becomes.
Azure is the right answer for most organisations, but the questions that make people hesitate are fair ones. What will it actually cost. How much downtime. What happens to the data. Will the line of business application still work. Get those wrong and a migration becomes expensive and slow to put right.