Solution - Go to Settings -> Home -> Enable Shortcuts -> Go to a new tab -> Google will be pinned by default, hover over the Google icon -> Click on the 3 dots menu -> Unpin
You can add ecosia without the extension, just open the website, click the url bar and it'll be among the search engines with a plus on top. Clicking it adds it
Try removing Google from your search engines. If you still want it you can re-add it from search results (click address bar, a new search icon with a + should appear at the bottom) or Mycroft.
Also consider removing/dismissing Google from the new tab page. If you have disabled the option showing your most visited sites, enable it temporarily to remove Google and untick the "sponsored" option in the new tab cog icon on the top right.
Solution: Go to Settings > Home > Enable Shortcuts > Go to a new tab > Google will be pinned by default, hover over the Google icon > Click on the 3 dots menu > Unpin
Context: if you dont block Google (and tons of other) Javascript and dont isolate cookies, Google already knows a lot about what you are doing. So you could also just use their search pretty much.
But if you block their javascript through an "allowlist" approach using NoScript, they cant place cookies or tracking pixels and you get a huge advantage