The lighting to headphone jack dongle is one of their highest selling products. Doesn't that prove the headphone jack is still relevant? People still use it. Pro Audio people still use it. If you are anywhere near a sound board in your life, the headphone jack is still relevant. So no, it's not courageous and it's one reason why I am using an S10 right now.
Old doesn't mean bad or obsolete.
There are so many reasons why professionals and audiophiles still prefer wired headphone over wireless.
At the current rate, BT will need another 10 years to match the sound quality of wired headphones.
You say "no one even batted an eye when the iPad Pro arrived without a 3.5mm port."
I did and I will not buy any iPad without an audio jack. The audio jack just works and nothing has replaced it yet. My 3.5mm audio devices won't plug into anything else. I'm not against wireless but wired is always simpler and more reliable.
No. Courage is not the word.
However removing the headphone jack just makes sense. Old tech. Time to move on.