To use the function keys on an old MacBook Pro, you have to chord with the "fn" key to override the brightness, volume, etc controls.

To use the functions keys in the touch bar in the new MacBook Pro, you have to chord with the "fn" key as well.

So where is the difference...

It has always been possible to set those keys to default to F-key functions instead of media functions. The difference here is that the position may not be constant, and you can't feel with your fingers what you're over before you commit to activating the function, so you must look. In some contexts you can "get used to it", but this is a steeper uphill battle.

I would not be surprised if one of the customizations of the touch bar is to set the function keys as the default.

Visual Studio is the only place I've really used the function keys (F5, F10, F11), and I rarely use VS anymore. Outside of that I use F2 when in any kind of GUI that permits renaming of a file or folder.

All of which can be rebound.

What about IntelliJ or Chrome or any IDE for that matter.

I use gdb and never use function keys.

If you have to use debugger then your code must be really bad