There's also facts: Gutenberg plugin adoption is growing faster than Classic Editor adoption, so it's not likely it will have more active installs than any other plugin. But even if it did, that's okay, we're supporting it. It's not a failing of Gutenberg, just showing that people for whatever reason don't want change.

AFAIK there is no change to database or memory usage post-Gutenberg, especially since pretty much all of the new code executes on the client side when you edit a post. It may use more memory in your browser, but not anything that should cause issues.