I play with every assist turned off and on the hardest settings available. I also don't use glitches or exploits. Everything I achieve comes from practice and skill.
You're absolutely right that it's impossible to compete with players who rely on glitches. In my opinion, this ramp has a legitimate score ceiling of around 12,000 points. Anything significantly beyond that is most likely the result of a glitch or exploit.
One of the main reasons I'm against assists in Battle mode is Vert Pump Assist. At 100%, you barely need to pump at all—you can simply keep pushing and still gain a huge amount of speed and height. Personally, I've never seen anyone ride a vert ramp like that in real life.
I play with Vert Pump Assist set to 0. If I mistime my pumps, I barely gain any height. It took a lot of practice to learn the correct timing, and I believe that learning process and skill gap are an important part of the game.
A good comparison is aim assist in FPS games. For example, Apex Legends currently uses 0.3 aim assist for controllers. Imagine if it were set to the maximum instead. At first it might not seem like a big issue, but eventually players relying on stronger assists would close the skill gap. That's why I believe competitive modes should avoid gameplay assists whenever possible.
The same issue exists in Street Fight. Some players use glitches to reach impossible scores. Even if you play legitimately using manual pumping—the strategy that currently gives the best results—players using higher assist settings can still score more than twice as many points.
Can Battle mode really be considered fair when assist settings have such a large impact on performance?
Back in Skate 2, I reached World Rank #12 in Spot Battle and consistently finished near the top of the weekly rankings. Everyone competed under the same settings, which made the competition fair.
The reason I play skate. on the hardest settings is because it feels the closest to Skate 2.
To be clear, I'm only talking about Battle mode. In Free Skate, I think everyone should be free to play however they enjoy.