And still you have no answer.
Are you feeling strong...
to hear the Expert tell you
"You're doing it all wrong"?
Just because it appeared to work, it doesn’t mean that it’s the right way of doing something. Perhaps it was never the right method. Or maybe it’s no longer the right method.
As it’s improved WordPress has had a habit of changing things so that you can no longer use a method that you used to use without getting a message about something being deprecated.
If you don’t keep up with development you can find yourself where something that used to work now doesn’t. And the first thing you see is a deprecated notice.
Some test cases written for PHP Unit 6 or earlier will not work under PHPUnit 8 until you change them. I missed out on seeing the deprecation notices in PHPUnit 7 since I went straight from 6 to 8.