Where are My Worlds?

I just booted up Minecraft for my nieces and nephews because I had 7 worlds I had spent over a decade working on.

They're gone. Gone. Nothing. Nowhere. 14 years of work. Gone. Tried on iPad. Maybe I can download on my Mac and it will be there?

I do not own an Xbox anymore and now because of this frankly why would I want to give Microsoft another dollar?