The problem with e.g. DCTs is that it can't do 0.x seconds consistently. It can only do that if they are switching from an odd to an even gear or vice versa whe

The problem with e.g. DCTs is that it can't do 0.x seconds consistently. It can only do that if they are switching from an odd to an even gear or vice versa where the target gear has been pre-selected. If the wrong target gear is pre-selected, it takes 1.x seconds. There are extra delays from where you'd want the gear to be engaged to the TCU noticing that it needs to be engaged to the gear actually being engaged. The former delays were quite dominant, esp. in older implementations (I don't know how much progress has been made). Both DCTs and converter transmissions require far more maintenance than manual transmissions (e.g. DCT requires oil change every 60k, overhaul after 180k). Changing gears on a manual transmission arguably takes more time, at least when the DCT has guessed correctly, but it doesn't matter nearly as much, because you, as the driver, are able to initiate the process in advance, because you have more information than the TCU, which approximately only has a tuple of (vehicle speed, engine RPM, current gear, gas pedal position, brake pedal position, D/S mode) to guess which gear to switch to soon. Also, automatics still mean you have to know and understand gears, unless you live in a very flat piece of land, or don't care about fuel consumption and wear.