Browser default focus indicators and SC 2.4.7

Is relying on the browser's default focus indicator sufficient to meet SC
2.4.7 (focus visible)?

Given that the default focus indicator in certain browsers is very
difficult to see,
it seems to me that if web developers do nothing, their page could be said
to fail on visible focus.

However, lately I've been hearing more recommendations that it's best to
just leave the browser's default focus indicator alone, based on the
premise that some browsers do this well, and changing the default display
messes with users' expectations.

Opinions?

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Terrill Thompson
Technology Accessibility Specialist
DO-IT, Accessible Technology Services
UW Information Technology
University of Washington
tft@uw.edu