Creating a server for version 1.21 allows you to play with friends using the latest Minecraft features like the Trial Chambers.
Given the pace of development (it took 2 years to go from 1.8.8 to 1.20.4), a may arrive in late 2025 or early 2026.
Take advantage of free Minecraft trials to experience the game without committing to a purchase.
Playing on a 1.21-compatible client or server gives you access to the latest mechanics introduced by Mojang :