Originally Posted by Dave Mayer

Tubulars dominate at the highest level of the sport, past, present and forever. The inherent weight, strength, and safety disadvantage of the clincher rim means that regular clinchers will only exist for the following reasons:

• For recreational or low-performance riding where the cost of the tubular tires, and the mess of gluing overwhelms the decision.
• Your third-tier team has no tubular rim or tire sponsor options
• Your second-tier team has a sponsor that wants to push tubeless to weekend warriors and dentists. After all, Pro racing exists to sell banks, lotteries and bike stuff.
• Your first-tier team is supposedly riding tubeless (for marketing) but is actually riding relabeled Vittoria tubulars.

Again, clinchers have no performance advantage over tubulars, and a big safety downside. Rolling resistance is a non-issue, because the riders who matter (team leaders) are buried in the pack 95% of the time until the big climb or the final sprint. Wheel inertia is all-important.