Yes, it's a fancy fuzzy finder for NeoVim.
If you're already familiar with and enjoy FZF or CtrlP-like fuzzy finders in Vim interfaces then the tl;dr is "Telescope is to FZF as Neovim is to Vim'. It would be easy to say "they're both the same picture" and that would be very true to a degree but I'd say Telescope looks like the next evolutionary step in this area to me because:
- it's written in lua (I know for NeoVim this is like 'X rewritten in Rust' headlines are for the general HN audience, but thought I'd get it out of the way. I do believe this will lead to a faster/bigger development ecosystem and also provide a very Vim-appropriate degree of configurability for people who want to invest some time in coding to tweak their worflow.)
- The "speed" issue is mostly about implementing async-aware stuff so nothing blocks. This is a general trend in Neovim and it seems to be going well but people who tried it a while back may have hit issues and not seen the full benefit of this yet as it's an ongoing process.
- Like Ripgrep, the fastest search is the smartest search i.e. that doesn't actually search everything, and the configurability and still nascent UI experiments seems likely to lead to some optimums here as people specialize in different things.
- It assumes you have a recent (currently unstable nightly) version of Neovim, and takes advantage of that opportunity to make full use of NeoVim core changes at the design stage. You could probably ask the exact same question of "Why do I want Neovim if I'm fine with Vim?" and there's probably many good write-ups of that question that will transitively apply here as well.
- Because the basic UI it provides is a sweet spot of 'pretty, usable, fast, easy-to-build-on, configurable' and they're working with this connecting layer in mind it looks like it might absorb/replace a lot of other plugins that are currently reinventing wheels in this regard and let them focus on the bit they actually care about.
But yeah, it wouldn't exist without those other things existing before it and I'd be more excited to introduce someone to this whole world of tools, than this one in particular. But anyone using these kind of tools, should try this out, and probably the first impression for those people would be, "Oh that looks cooler" and then shortly after "I'm going to write my own plugin!".