https://www.minecraft.net/en-us/article/java-edition-moving-house Looks like Mojang is removing Mojang accounts and forcing all users to migrate over to Microsoft accounts. Most annoying part is that you can't have multiple MC accounts linked to one MS account, so you need to create one for each of your alts.
zzzzzzzzzzzzzz microsoft account zzzzzzzzzzzzzzzzzzzz shoving microsoft edge down windows 10 users' throats zzzzzzzzzzzzz no i do not want cortana and bing search zzzzzzzzzzzzzzz
Now everyone and their dad is going to have a cape lmao. I'm not a big fan of the move at all since Microsoft accounts are pretty much the most useless thing on the planet. On the plus side, it's going to be better for account security but that can kinda be a pain in itself since its Microsoft.