If we don't want the idea to be gradually chipped away until it's meaningless then yes, we need to draw a line in the sand and say that open source can have these restrictions but not those restrictions. And thankfully we already have that: the OSI's definition, Debian's DFSG, and the FSF's Free Software Decision are all substantially equivalent and represent a clear consensus on what is and isn't open-source; one that a lot of care and thought have already gone into.

Talking about categories of things are useful. This is like saying "Do we really need a term for two-wheeled vehicles driven by pedals? Just say you have a Cannondale or a Schwinn."

>Do we really need a ‘legally clear’ definition of open source and free software?

The FSF has gone to great lengths to give a legally clear definition of free software. Something like the SSPL is not free software because it restricts Amazon's freedom to use the software. Stallman has always had an ideological goal when it came to Free software.

Not just Stallman, but OSI was founded with an ideological goal too. It's goal is to strip ethics from software development and focus solely on technical and economical output for companies while Stallman and FSF had focused exactly on the ethics of software development.

The Apache are a group of culturally related Native American tribes in the Southwestern United States. I'm pretty sure none of their tribal authorities have given you a license for your software.

Are you unable to use any of the several free search engines available on the web, or are you just making a point?

Either way, this is relevant: https://www.apache.org/apache-name/