All in all, insufficiently broken for me to be bothered enough to turn it back off :). I do wish there was a "view from alternate origin" feature though, to let me load a site as if it were loaded in an iFrame -- that would let me work around the issues with my internal sites.
Well worth it since they are superior to Google. For email, Fastmail is king.
And use GMail as an MUA and am the GSuite administrator for the school I support.
Using Google is a trade-off, and there are definitely services they provide where the trade-off is worth it for me. Your mileage appears to vary. First-party isolation definitely kicks the needle across towards Google only having data I'm happy for them to have.
Also, there are Google search-proxies like startpage.com
site:news.ycombinator.com in google.com
About 11,90,000 results (0.25 seconds)
Kind of frustrating :-/
Also you can use startpage.com for searches, it uses Google behind the scenes. Looks nicer too. :)