[Stranger43]

It's usually a cost decision and AWS don't really care about anything smaller then say the US government enough to even attempt to engage in competitive bidding proposals so if a company/organization put out an RFP MS usually finds a way to look cheaper then AWS.

Add to that that AWS dont really engage in the normal business to business sales process but simple gives you a price list and tells you "thats what it costs" pretty much straight up and it's no surprise a lot of traditional enterprises with huge existing Microsoft bills end up with the vendor they know, understand and think they can control.

It's not that there is anything really wrong with AWS their support is good their products work but it's a messy platform where you really need to pay attention and might even engage with consultant to fully understand what your paying for and how optimization decisions is affecting your ROI as everything is priced individually in AWS where as Azure does a bit more bundling into packages.