Yes of course, being flexible doesn't in any way automatically lead to better kicks, but at least for me, being flexible helps with getting the force of the kick all the way to the top of it, if you know what I mean.

When I wasn't as flexible as I am now, at least I personally found that the muscles on the opposite side of whatever I was kicking with sort of added resistance to the motion for some of the kicks, slowing them down towards the end of the technique.