I had bought Minecraft before Microsoft bought Mojang, and eventually I was forced to migrate my Minecraft license to a Microsoft account.
After I had successfully created the account, logged in, and transferred the license, and ONLY after I had transferred the license, I was suddenly locked out of my account until I provided a phone number.
I will never buy a Microsoft product again, and I think I've done a decent job reducing the amount of their stuff that other people have bought, as well.