I recently had to deal with Entra ID for the first time to setup Microsoft OAuth for our site and my god why is it so badly designed.
Just creating a tenant is a PITA and you get a default tenant you can't change without paying for Microsoft 365? Then you have subscriptions, Microsoft partners, Enteprise vs individual accounts, etc. All mixed with legacy AD naming and renaming, documentation with outdated screenshots, Microsoft Partners bullshit.
There ist a whole industry clustered around this FUBAR that makes its living by helping companies navigate this shit. It has small and big players and they have no incentive to tell you that there is anything else you could use. The monthly Service fee is too tasty.