In which version do you play Minecraft and why?
Always in the latest version (including snapshots)
1.8, 1.15, 1.16, Beta 1.7.3, 1.7 (for Modpacks)
So mostly I play on 1.10.2. Now and then 1.12 or 1.14
1.8.9 when I play on Hypixel.
1.12.2 when I play Modded.
1.13.2 when I play on uwmc.
1.15.2 when I play Vanilla.
And also with your important worlds that you have built? Because the problem is that it is strongly advised not to open important Minecraft worlds at Snapshot, as it can be a bug that your world will be destroyed.
Backups…
Yes, if you do backup then. Otherwise wait until the official version comes out.
1.8 on PVP servers
1.13.2 On Klickmich and Optifine
1.14 on building servers / CB and Vanilla
1.15 / 1.16 for testing