It's the result of all the factors, cumulatively. Tech has advanced, but even back when Tech was adding NEW at a much slower pace, advances were happening at a very perceptive pace.
The science of training, prep and decision making have constantly sped up advancement. Obvious in all things, and certainly in all things athletic.
Sure, the new tech has a part in this, but not as great as the elements of applied science as comes to human overall abilities, fitness, knowledge and ability to react and adapt.

Let's not forget that even though there are a very few incredible standouts, the entire population of riders , female and male, are all exceptional examples of what humans are capable of on a bicycle.
And, of course, Tech is 'slowed', hindered, regulated by the governing body of world cycling. If tech was unbounded, we would see even greater 'advances'...
We enjoy the fruits of all these 'advancements' and it makes riding maybe more pleasurable, fulfilling and whatever else we get out of it. But the tech whether 10 or 30 or 90 years old, still brings great enjoyment and fulfillment (if we ourselves acknowledge and appreciate it). So I still get great pleasure and fulfillment from riding my grandfather's bike from 1939.

Of course 'speed' is not the real advancement (Intent, other than the '1st to the Line' thing). If bicycle performance was completed based on 'speed' (without consideration for tech) we have gone beyond Human powered speed some centuries, millennia ago.
SO the major consideration and foundation of effort is 'HUMAN' effort and ability.
Under that parameter, the advancement of human capablity is still apparent, obvious, undisputed.
And the remarkable, notable is the effort of individuals against other individuals and the whole (Riders and Peletons).
The true and remarkable part of Road & Mtb and many other forms is not the 'Finish Line', it's the story, endeavour of how it's reached.
If you've ever 'raced' a bike, the 'win' is of course a great result, but I believe that reaching the 'end' of a race was never a total disappointment for non-winners. There is always a strong element of 'accomplishment'. It would have to be true for those who have 'worked hard for many miles/kilometers and finished well behind the 'winner'.
Science has added to the Human endeavor greatly, and allowed us to realize more accomplishment. I'm particularly aware of that, being 77. I look back and around, and I see that, inspite of my disappointments in myself, I see my capabilities are more than what was considered 'reality' not too far back in time. some of that is 'tech', knowledge and adjusted expectations; some of that is just a more focused 'me' on what I might be capable of.

New tech is great, But it's the rider...

Ride On
Yuri