PyCharm is an open-core editor. The FOSS edition is a second-class citizen. I make a point not to run any proprietary software on my machine besides occasional whitelisted JS, firmware, and patent-encumbered media codecs (which still have free implementations).

Neovim's master branch has a built-in Language Server Protocol client and Treesitter implementation, both of which have pre-made configs for Python development. Jumping between symbols, viewing floating documentation/signatures/git-blame, asynchronous completion, diagnostics, etc. are all readily available with a fraction of the battery/CPU/memory usage on a fully-FOSS platform that works on even more platforms (BSD, over SSH, etc). Jumping between symbols and listing usage of an object in a project with hundreds of files has never been faster. All this starts up in milliseconds. Being able to use an editor advanced enoguh for a large project but lightweight enough to launch with a keybind just to write the HN comment is amazing.

Here are some screenshots of the LSP and treesitter in action:

Floating documentation and diagnostics: https://i.imgur.com/0TYi5en.png

A small taste of Treesitter's highlighting + navigation features: https://i.imgur.com/wrSpJ2X.png

Completion from the nvim-lsp source: https://i.imgur.com/CzAAJuC.png

Neovim also has FZF integration to fuzzy-search thousands of symbols, files, reference, etc. Since it's the same FZF that I use everywhere else underneath, the interface is quite familiar.

TLDR: Neovim is a lightweight text editor that integrates with external tools to transform itself into an IDE.