In a game were progress (even personal progress) is measured in less than a second, yes there has been significant progress (read: times are getting faster). But, they are all considered marginal gains.
So, the tech itself hasn't changed much (aero tubing, carbon fiber, 34cm Nitto B123 bars have existed for decades).
What's changed is data analysis. Athletes and coaches being able to get instant data and the knowledge of how to analyze it to look for these marginal gains has increased. A coach and athlete can test an idea that's "ass backwards" and beyond all "common sense" and immediately see if it works. I mean, it was just 2009 when people were like, "You NEED wide bars in order to breath! Hell, even 40cm bars are too narrow!! You can't handle the bike with bars more narrow than 40cm!".
So, it's data analysis that's changed. It was that sea change that vaulted Team GB over everyone else in the world. They were one of the first teams to put computers and power meters on every bike and hire a full-time data analyst (who later married Victoria Pendleton) to analyze that data for actionable insights.