Sure the configuration file is retro compatible, but some of the plugins are better suited for neovim and vice versa. I use a dozen of them and if I switch permanently to neovim I'd like to start fresh using more "modern" alternatives that make use of the newer features.
I ended up moving to Kakoune. The community is small but the tool is so much better designed and integrates well with unix. That means that i can usually glue together whatever I need myself with 1-3 lines of config and don't need an entire plugin when I want something that isn't built-in.
I also have seen that the very first time I tried neovim. Some people may like it but I consider a terminal to be as simple as possible. Furthermore, I use often the CLI on non-GUI terminals where such non-ASCII characters can have various side effects (e.g. unicode bars, braille like progress bar and so on, those destroy your serial terminal line).
I don't think I've seen plugins with animations (nor would I want to). Agreed that emoji in the terminal, modulo useful glyphs like language logos next to files in a directory tree [0], are distracting.
What I don't understand are people who add a million plugins, and then wonder why the startup performance is terrible. I have a fair amount, including some I honestly rarely or never need, and startup time is still 75 msec, which is fast enough for me not to be bothered.