companies will have less of an incentive to produce gliding vehicles when they could just instead copy or improve upon the Falcon model.

That's assuming any competition even survives the next few years. Pretty sure the only two competitors still doing orbital launches are United Launch Alliance and ATK Orbital, and their launch volume has already been totally dwarfed, their prices undercut drastically.. I don't see them surviving, let alone getting the capital together to make major advancements.

Blue Origin is trying, but there are no results yet. At best it's a potential future competitor. Still gonna be hard to compete with SpaceX in any meaningful way from this far behind the curve.