I never had a single “website blocked” dialog because of safe browsing. Meanwhile UBlock Origin often blocks websites, fullscreen with a warning.
On Firefox Safe Browsing is proxied through their servers and anonymized, so I use it. But tbh I have no idea how useful that is?
I use Search Engines (DDG, Startpage, SearX) or Bookmarks and never had such a block, does it directly filter those sites from search results?
Browser manufacturers receive reports from users of known malicious sites, and use that to form a blocklist. The browser downloads a copy of the block list and compares it to the URL of the page you’re going to.
Only then does it show a big scary red warning.
Search engines are known to do their own work in removing malicious sites. They aren’t perfect and some do fall through the cracks.
Thats what I mean, I never got such a warning screen. But I also use UBO which probably replaces that completely.
The warning screen is a privileged page in Chrome and Firefox. Extensions cannot tamper with it.
More likely you simply haven’t been on a page confirmed by the browsers to be phishing or malware. As you said, you mainly go from search engine results, which do their own cleanup