Sure, but they'll have to catch up on almost 30 years of feature development (and feature creep). Active Directory is entrenched, by virtue of being the only game in town for decades.
Not that they're necessarily irreplaceable, but... a half-competent Windows Server admin can go from cold iron to running HyperV with a local domain (AD forest) with a SAN supporting 200 endpoints (assuming the hardware is already in place) pre-configured with end-user applications and all relevant network & security settings (via group policy), with a print server supporting local network printers, and be ready to enroll new users, in less than a day.
I've seen it done, I've helped get it done. And all of that can be done with point-and-click GUIs, and not a dozen different ones, just like 3 (one for server/HyperV deployment, one for HyperV config post-install, and then basically everything else can be done through Active Directory).
When you're a sysadmin for a large organization, that kind of operation at scale is non-negotiable. When I say that AD really has no competition, that's what I mean. You could accomplish all of the same things on Linux, but it would take you a week of punching through terminal commands just to get the server and the domain up and running, and once you were done the user management still wouldn't be as flexible or feature-complete as it is on AD (especially if you need things like auditing, or physical access token integration like badges for authentication, or remote desktop support, or video conferencing that is linked to corporate email accounts).
All of that said, if you happen to know of a group that's actually working on a competitor for on-prem AD (not Azure AD/EntraID, the cloud system is very different and not really comparable) I would be very interested. It's a problem that's been on my mind for awhile now, and I'd love to get paid to actually work on it.