Nobody responded to that because it's utterly unrealistic in modern F1 cars. The technology will have to be rolled back QUITE A LOT for manuals to be workable option. I remember reading about Senna's mechanic taping his gearshift hand before the race so he doesn't tear it to blood...Notice how no one responded to this !
You watch a lap viewing what the driver has to do to go that fast - no way manual.
Make the engines bigger, sweet sounding, manual trans and no electronics and you have the 70's.
Probably would be more enjoyable to watch and listen to - but never going to happen.
Just watch video of old races.
If we are talking about fantasy world - yes, give all the drivers exactly, exactly, the same cars, with manuals and V12, and i don't really care about teams.