RHEL 10 announced that RDP would be the preferred alternative to VNC. Red Hat replaced Spice with VNC in Red Hat 8 due to licensing issues with h.246. VNC is under featured and basic compared to both alternatives. Spice uses proprietary h.246 which caused disputes with licenses. RDP is proprietary to microsoft but has a few foss implementations.
@jrgd @potentiallynotfelix It is simply less capable than Spice, no support for accelerated 3D graphics.