You can still see improvements in physical ability with any lifts without needing to be at the limits of your strength. The intra- and intermuscular coordination that more complex lifts develop will benefit running, tackling and other movements without needing to be at some arbitrarily defined heavy weight. If you take that argument to it's logical conclusion you end up saying that the best thing for sports would be training on isolation machines, making the only limiting factor how much force one muscle can generate. It's not realistic. Just learning how to 'triple extend', even with not much weight, is going to be beneficial particularly to younger athletes who need to develop proprioception and coordination.
Also, the olympic lifts are not so much about getting strong as getting fast; developing force as quickly as possible. This does not need to make use of maximal weights; far from it. Look at Westside - 50-60% of raw max as fast as possible. You don't need to use 90+% of what your body is capable of to develop some athletic qualities.