Without leaderboards or gold/silver/bronze times, licenses and circuit experiences are pretty useless. It's just driving a random car around a section of a track.
The fact that PD spends so much time on time trial-y sort of things in single player and yet doesn't actually give us any ability to actually time trial with them is just so dumb. I don't get it.
I'm all for playing devils advocate and challenging someone's assumptions or perspective, so allow me to present a different interpretation of the license tests, circuit experience and their associated leaderboards.
PD want to encourage racers to learn driving techniques, so they create the license tests. These tests give you a car and section of track specifically to teach you a technique that may be needed on that section of track.
PD also wants you to become familiar with the circuits, so they create circuit experience, with both a brief written guide and demo ghost to teach you the lines, braking points etc.
How do you encourage players to do this content? You give them levels of pass - bronze, silver and gold, and you tie rewards to the different levels. Everyone will want the gold for the best reward, which also ensures they'll practice the technique or track, which will make them better!
That is the purpose of the license tests and circuit experience. But people want to compete at everything. People want to beat their friends at things and some people want to push to be one of the best in the world! How do you satisfy those people? You give them a leaderboard and that's it. No rewards for being in the top 10%. Just a leaderboard and bragging rights.
That's what the leaderboards are. They're not an attempt at turning license tests, circuit experience or missions into time trials. They're a way for you to compete, purely for bragging rights, with friends and other racers, and the irony is that most of us will complete the event, get the gold, maybe check where we are globally and then move on, never checking again.
Now, I understand some people's frustration that having spent hours learning the finest points of a track to maximise their time and position on those leaderboards, but my point still stands - just redo your times.
The adjusted physics made some cars easier to handle. If you've spent hours learning a track and some schlep like me beat your time in 3 attempts, you should know this track well enough to beat my time with ease under the new physics. And isn't that what the leaderboards are for? You post a time and someone tries to beat it, if they beat it you try to beat their time.