i3 isn't even snappy, the default application launcher can take up to 10 seconds to open on my old laptop.
There is a faster application launcher you can use instead, but you have to hunt through github issues to find out about it. The i3 project maintainers seem to actively object to telling users about 3rd party components and simultaneously refuse to integrate them or improve the default behaviour.
https://github.com/i3/i3/issues/949
Reported 7 years ago...
Of course, the problem is often that with other options some assembly is probably required. But looking at the mess gnome extensions are, that might actually be not that much of a difference.