How does gNB decide which UE to serve?

Hello Experts.

Just a philosophical question:

If we have eMBB users and we have IoT users and 5G NR base station serving in SU-MIMO.
Then at each time frequency we have one UE served at time.
How does gNB decide which UE to serve?

SU MIMO means only one user per PRB at a certain slot, and in one slot more than one user may be scheduled by sharing the PRBs, aka FDM. MU MIMO you will reuse the PRBs at the same slot by scheduling the same PRBs to different users which are geographically separated.

*the dividing the total amount of PRBs, a better selection of words.

Which UE is served in next TTI is decided by scheduler profile: max CI, round robin or proportional fair or enhanced proportional fair