As I was saying. That's not a valid reason for including something. We don't include low poly car models just because they were in previous games, we improve them, so why can't they improve anything else?
..and why do they need a specific test to learn that? There are hundreds of racing games out there, GT is the only one that has these super basic tests. Other games send you out to the track and you learn by experience. That's how we learn a lot of things as humans.
When was the last time you ever saw someone complaining they didn't like a racing game because they just didn't understand how cars braking worked? You quickly work it out, even in a game like F1 which are nothing like cars anyone drives in the real world. People work it out.
Who told you it's mandatory to learn technique thru the driving school? It isn't. There's nothing inherently invalid about just hopping in a lobby or race and sharpening your skills in there, if you don't want to jump thru hoops. I'm pretty sure PD won't hang a red banner over your car that says "LOOK OUT, I NEVER DID THE STRAIGHT LINE BRAKING LESSON".
I like the presence of these tests, repeatable controls you can use as a yardstick for progress, and the value you get out as with all training is equivalent to what you put in. You might not have a use for a straight line test as it stands, but what if you buy a new pedal set? What if you just want to try braking with the new haptic triggers in the most repeatable way possible, feeling for the ABS bite etc. Removing as many variables as possible is good for testing.
You're essentially complaining about the presence of these basic tests because you're beyond them, which is great, and yeah, most people who pick up the game are gonna be beyond those first two. But it will take less time to clear those tests than it has taken to write these posts, and it's safe to assume later tests will certainly present more robust and relevant challenges.
Just because you don't personally need it, doesn't make it a waste of development time. I don't drive 911s, but it wasn't a waste of time for PD to model however many of them, purely because they're not to my personal taste. That's a stretch, but, you see my point.
Regardless of whether it's a classic GT callback or a symptom of being stuck in the past, it's such a nothingburger of an issue I can't fathom getting annoyed about it.
EDIT: for me personally coming to GT sport from a pure rally game background, I did find the straight line braking tests useful in accounting for different weight and braking distances, and trying to brake in one smooth motion rather than braking in stages like one often does in technical rally sections.