If I remember correct, when a macro is called, the '%' trigger SAS macro facilty and it first goes to the WORKING library to find the macro and excute it. If not it goes to the defined autocall facility library to find it, complie it and excute it. If the macro is already complied, then the compling process is skipped. That is all I see the difference. When I was a SAS developper, I stored all macros into the autocall library which was defined when a user launched his SAS session. Then all macros were available for everyone.

BTY %include is not part of SAS macro facility. Yes, it could do 'the same/sort of' macro functions if one writes the SAS codes dynamically and include them later on.  But one can use SAS call execute routine to do the same job now.

Before SAS macro was invented, %include was to the approach to do the dynamic programming in SAS.

HTH