This is already answered in your previous post
Also here - https://stackoverflow.com/questions/29149308/how-to-setup-ssrs-with-an-azure-sql-server-database
Maybe they didn't want to focus more on SSRS and focus more on Power BI for reporting or had some difficulties in providing support with Azure SQL.. Not sure.. it is simply not supported
Anyway, you just have the option to use SSRS inside Azure VM.
Edit #1 - Take a look at similar post - https://stackoverflow.com/questions/66457672/ssrs-on-azure-sql-database-why-its-not-supported
Please don't forget to Accept Answer and Up-vote if the response helped -- Vaibhav