It’s not even just technology though it’s role is undeniable. Humans are almost certainly improving as well in two ways:
(1) Sampling: Mathematically, if you keep drawing more and more samples from an unchanging but infinite “talent distribution”, the maximum value will keep increasing over time unless humanity lucked out and found the absolute maximum already in the past.
This is like saying if you keep tossing a coin and keep counting the maximum number of consecutive heads, within, say, 10 million flips, you will keep getting seemingly ever increasing counts.
(2) Evolution: Humanity’s talent distribution is almost certainly not stationary but improving over time. If there is any component of running that is genetically determined, interbreeding over time is overwhelmingly likely to produce humans with ever increasing potential. It is theoretically possible for breeding patterns to occur in a way such that running talent is lost over time, but not if mate selection is essentially randomly selecting random mates or selecting a mate who also has good running potential (as opposed to everyone consistently selecting terrible runners because, say, running talent is an existential liability and therefore gets evolved out slowly).
This is like saying if you keep finding new coins in nature that are equally likely to be biased towards heads or tails or more likely to be biased towards heads (but not systematically biased towards tails over time), and keep doing the consecutive-heads-counting experiment described above, you will keep getting seemingly ever increasing counts.