/Teams/ and /Sites/ site address options not available for Team sites but is for Communication sites

I don't know if they will ever add that to the Team site creation or not (it would be nice if they did), but alternatively you can change the default managed path from /sites to /teams through the SharePoint Admin Center. If you make the change there, then both Team and Communication site will be created at /teams by default. However, as you have stated, with the Communication sites you will still have the option to change them to /sites during creation if needed. 

Also, you could check out the Microsoft 365 Roadmap to see if they are possibly working on this feature. Roadmap: https://www.microsoft.com/en-us/microsoft-365/roadmap?filters=