https://nvim-orgmode.github.io/ is very good and very customisable while keeping consistent and open file file format that allows your notes to be easily stored and read by other apps.
Not very easy but not very hard either. Obsidian works with .md files they have close syntaxes to .org files that orgmode works with, but you will have to convert them.
I would also suggest searching for some neovim plugins working with .md files. That will allow you to directly import your files. Something like this maybe?