Thanks to him, you will not fly off the bike, doing various tricks, etc.
Q&A: Are there any glitches (bugs), are they fixable? No, but there is a side effect - the cops (and not only) cannot throw you off the bike. When falling into the water, the player flies off the bike, because. otherwise the game crashed. Well, sometimes, when you sit on a bike for the first time, Tommy flies off, so, sitting on him, fit into the wall to check, and only then do tricks and get the cops. And Tommy can (sometimes) fall off if you flip your bike in the air (as in the screenshot).
Are other versions expected? No, this is the final one.