There was a study carried out on what kinds of data leaks on browsers during launch [0] but Chromium specifically wasn't measured. I can only infer Safe browsing to be a leak point available on Chromium since it is shipped by default but I have it turned off (never needed it anyway) so I have not observed any pings related to it personally.
[0] https://www.scss.tcd.ie/Doug.Leith/pubs/browser_privacy.pdf
> What I found were dozens of requests, which loaded nearly 16 MB in data. Lets break down what I saw.
> I also reviewed Google Chrome, for those interested: When I launched Google Chrome for the first time (and let it sit for a minute), 32 requests were made, and 7.26 MB of data downloaded.
Presumably Chromium would ping even less than Google Chrome.
You cannot be preaching about privacy and refuse to provide a simple toggle to opt-out of all telemetry in your software.
FYI I do use ungoogled chromium as my main browser.
That's why I use LibreWolf: it respects my privacy and autonomy, and I help fight against Google's growing web engine monopoly. I specifically don't use UnGoogled Chromium because I don't want to look like "just another Chrome user" when companies decide whether or not they should test web apps on anything besides chrome, or prioritize non-chrome bugs.
Seriously, give LibreWolf a shot. It's a very minimal fork of Firefox that just removes the Mozilla botnet parts of the browser, so it should be (relatively) easy for maintainers to keep it going for the forseeable future. You can install and update it with homebrew. And, y'know... you're not helping Google push around web developers with Manifest V3 ad-blocker killers, AMP, FLOC, etc.
Biggest reason I refuse to use Firefox no matter how bad Chromium is. I sometimes use Firefox Focus for doing searches on my phone and the thing is always pinging mozilla services. Some of them location related. No way to turn any of these off on what is supposed to be an incognito browser.