Is weight training a waste of time????

Is the title of this video click-bait ... ??? I don't think so.
To get the most from your long, triple and sprint conditioning what you do away from the pit or the track needs to be transferable and relevant. There are many who swear by weight training and "need" to lift weekly - however, there are many who lift much less sparingly without their performances suffering. and in fact improving.
If you are a regular reader of this blog or watcher of my YT channel videos you'll know that I don't place weights at the top of my "conditioning hierarchy". I'd rather spend time working on technique and speed and using plyometrics and sets of different sprint drills to develop what's required. I do however, see weights as having a role and that's to create robustness - that required to withstand injury (but note that this can also be achieved via many other means such as Swiss balls, and body weight exercises). I also value weights for the more conditioned athletes in the group and in particular utilise Triphasic methods - that's combining eccentric and isometric weights exercises with the much more common - and dare I say after a while, less important - concentric one. 
Also, by combining weights and plyos into a workout (Contrast/Complex training) you are more likely to get a heightened fast twitch muscle fibre and motor unit response - so this is something that we do regularly.
The video below goes into more detail about my thoughts on what weight training to do to really  improve your sprinting and jumping. It also looks at the limitations of a more traditional approach.