Your understanding of the manual gearbox is not correct. Yes the gears remain in constant mesh, the gearbox does NOT do anything by itself. The driver (only) moves the selection hub which engages that gear (i.e. connects it to the output shaft). So yes when a driver changes gear using a manual gearbox, there is NO automation, nothing is done by itself, the driver has to select the gear they want and engage that gear ... MANUALLY. And if you do not time the clutch actuation correctly the selection hub will protest and get it's teeth worn/damaged.A stick shift appears to be direct but isn't really. The vast majority of drivers could not and in any event do not shift any gears. The gears remain in constant mesh. All that the lever does is move a sleeve inside the transmission, the gearbox does the rest. What is the minimum requirement for the full Monty manual transmission experience?
This is why I do not like paddle shifts. The cars I have access to, due to my financial position, are actually just automatics and the paddle asks the computer controlled automatic transmission to change gear. There is such a massive delay as this happens it is pathetic. You end up having to account for that delay and hope that you calculated it correctly ... just weird and useless.
Now a Ferrari 458 will be very different, but my families old Labrador could change gear just as well as I can if I put peanut butter on one of the paddles. There is no personal satisfaction of a skill mastered there ... unlike when I change down in my 156v6, with a completely unnecessary heal and toe blip (just to prove to myself that at 51 I can still do it) and double de-clutch (again completely unnecessary but the gear slides in ever so smoothly, making me feel very satisfied).
I am a car enthusiast, not because I like the look of them, the sound, speed, etc. but because I find driving them satisfies something in my brain, and makes me feel enjoyment at a skill (I think) I've mastered. And the neat thing about manuals, is that you can practice that gear changing skill at all speeds, i.e. even with my family in the car just going shopping, when steering, accelerator and braking inputs for other driving factors are so below any levels that require skill there is no possible satisfaction enjoyment (woo hoo, you have turned into a shopping centre car park at 20 km/h, does not engage that something in my brain)