I believe it was Pompeo who recently said that. It's about right for some of the things going on lately.
Any software from China or Russia falls into that category for me. Some other places would too if it was more common to see mainstream software from them.
I agree with you on the web browsers. Hardly anyone uses an open source browser though. Most of them have open source components mixed with closed source blobs to the point where you don't really know what it's doing. Chrome is a good example where they go as far as to scan your machine for malware, but it's not the only one.
In software industry, following the "distrust and verify" strategy makes particularly good sense. Software that is not open-source cannot be verified, so should only be used in carefully sandboxed environments.
In 2020, why would anybody use a closed-source web browser?
[1] https://en.wikipedia.org/wiki/Trust,_but_verify