Sports has a vested interest in seeing records broken. Breaking records increases public interest, attendance, viewership, and clicks. More of these things means the ability to get more money from fans and sponsors. The UCI did ban “exotic” time trial bikes some years ago, like the Pinarello Sword. But the decrease in use of certain performance-enhancing substances slowed down riders. Faster bikes allow modern riders to ride faster than previous generations without chemical assistance. No one today on an early 2000’s bike could come close to matching the drug-induced performance of early 2000’s pro riders.