A world that me and my friend were playing on for about 5 year got reset by the new update

Hello, so on Sept 21st me and my friends decided to play minecraft, to have some fun so we went on the world, we have been playing on for about 5 years now, and when the host started the world they found out that the whole entire world has been reset, we tried some stuff to fix it and nothing worked we tried from getting rid of datapacks, all they way to changing the world files out for new ones. we i was wondering it there is anything we could do to get the world back.

the image attached is what happens when i put the db folder of the old world in a new world