Cadillac doesn't need a convertible. Cadillac needs things GM will never give them. That would be not just a CT6 based convertible to take on, if it can, the S Class. That would also be a CT4 coupe and convertible. That would also be a CT5 coupe and convertible. And a CT6 based coupe. Also, how about a front engine, RWD 2 seater that can put it to the SL, not just in statistics, not just in race track stats, but in the things that have over the decades made the Mercedes Benz SL what it is.
To put it simply, they probably needed to take the fight to Mercedes Benz in every market that it is in. So far, the patience and the resources to see these things through has been totally lacking. Allante was a nice start, but it needed at least a couple of generations to evolve. The same goes for every segment Cadillac has sought a toehold in for the last two decades. ATS, CTS, CT6, all of them needed time to become familiar to customers, and the money to truly develop the best in class. It doesn't cut the mustard to develop a fantastic chassis and place the cheapest part of the car directly into the driver's face (ATS, CT6). Of course, one has to question how Mercedes Benz sells what they do in their non-SUV non-crossover ranges,especially in this country, which is so crazy to drive what are essentially station wagons and bloated economy hatchbacks, but somehow, they've had the means to do it. Why can't Cadillac match that range?