[UPDATE - 4 Nov. 2023: Warning… The github page that hosts “Chromium Legacy” builds is now at least 3 versions behind the current Chromium release (as of 4 Nov. 2023). Even if it were up to date, it is a lot of work to continuously check the Google Chrome stable releases blog for Desktop releases and then manually download / install each new iteration. Chromium Legacy has no auto-update mechanism and will not notify you of updates as they become available.]
(original post:)
OK, I somehow forgot about Chromium Legacy that supports older macOS 10.7-10.14 and has pre-built downloads. Just pulled Chromium 117.0.5938.132.1, checked it with VirusTotal and ran it on a macOS 10.14 system with no major issues so far.
This build of Chromium wants to access the keychain but I Denied it as this browser will not be logging in to anything.
Chromium Legacy for macOS 10.7 - 10.14
(see Limitations list; some features not available; some UI issues)
Stable builds are based on Chrome’s stable channel branch and passed a few basic tests (launching, HTML5/JS tests, media playing) on 10.7 - 10.14.
I have Edited my first post to include Chromium Legacy and add emphasis to the danger of using older Chrome versions.