Unpopular opinion: unit tests are often overrated.

Although a well written test suite is almost essential in some parts of the application (I.E. business logic) I cringe when I see hundreds or thousands of line which “mocks” everything to test a micro service which just does CRUD operations on a database, in cases like that unit tests are just a waste of time because almost every operation involves a mock which may not behave like the real database and often needs to be rewritten when the code undergoes a huge refactoring. In these case a integration test suite is faster to write and way more helpful.

Unpopular opinion: although Windows 10 improved in the years Windows 7 is still better: Windows Search on 10 is almost useless and the control panel and many “modernised” system utilities often glitches, the system looks cruder and takes way more system resources than 7 without giving significant features in return.
Newer is not always better.

Unpopular opinion: OpenShift is just plain vanilla K8S with a thin marketing layer.

Unpopular opinion. IE6 stuck around for so long because it was the best browser in its time. It's horseshit today but only because that generation liked it so much they couldn't bring themselves to leave it.