Why would I have to buy Minecraft again?

I've had a problem lately that the Minecraft launcher is no longer loading the game properly, so I wanted to download Minecraft again. However, the website now says that I should buy it, even though I bought it a long time ago, as I said.
I'm registered and everything is correct.
Why am I being "forced" to buy Minecraft again?
What can I do about it?

If you are logged into your Mojang account where you own MC, you should be able to download MC without any problems.

This link should show you the Minecraft game you bought in the My Games area.
https://account.mojang.com/...ang.com/me

The download options (Windows | Mac | Linux etc…) should then be displayed on the right.

Thank you very much. I probably would never have found that alone.

Yes, I also had the company Microsoft bought it, just go to your minecraft folder and start it there

If you press "buy", the site will check your account and find that you have already bought it and release the download.