If I want to run something in background, I just Cmd+number to another window and run it there. Thanks to multiple panes & windows, I can have N things running “in background”, it takes a millisecond to switch to any of them, and I guess if I bother I could even have window tab title reflect the status of the process.
I’ve seen floating windows in Neovim, but I see only one use for them: expanded LSP error messages. Otherwise, I use floaters when they come plugin’s config, but they are more of a nuisance and are tricky to manage without resorting to pointer device.