Why disable powerups?

I noticed after playing Temple Run 1 for a while and fully upgrading my powerups that there's an option for disabling powerups. My question is how game mechanics handle this decision, and I have a couple theories:
Powerups in general have a constant chance of appearing at specific intervals in a run, and disabling a powerup allows other powerups to occur more often. e.g., constant chance of 10% in general, so 2.5% chance for magnet, invisibility, boost, and mega coin, and disabling one of them allows the remaining 3 a 3.33% chance of occuring.
Each powerup has a specific constant chance of appearing at specific intervals, (e.g., 2.5%) and thus the overall chance of any occuring is 10%, and disabling one of them reduces the overall probability to 7.5%.
I can see why disabling powerups would be advantageous in the first scenario if you have a preference for specific powerups, but I have no way of determining which of these mechanics are what's happening. Can anyone verify either of these, or state if there's actually a different mechanic than either of those going on?
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What is the meaning of powerups in Temple Run?
Powerups are collectible items that appear in Temple Run. Powerups randomly appear in the game in different places, and each have a different effect. Powerups also can be upgraded in the store.How do I turn off power ups on Reddit?
How do I turn off Powerups for my community?[TUTORIAL] How to disable Power Up In Standby PUIS from Windows
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