The trust is in different areas. The risk that Google would ship something that steals your passwords, addresses, or credit card information and does anything harmful with it besides ad targeting is basically zero. You know what you're getting with Google for the most part. The risk in the case of downloading random binaries is they may actually steal your information and cause real harm beyond ad targeting.

If you want chromium without Google there are several options such as Edge, Opera, Brave and probably a dozen more I've never heard of.

I trust that Google will abuse my personal information for monetary gain via advertising. I also trust that their compiled versions of Chrome will not be a ticking time bomb of ransomware.

On the other hand, I simply don't trust internet randos, much less to install their binaries.

And it seems like a third option of Firefox w/ uBlock is less bad than either of the above.