Hmm I disagree that most external gear has wet/dry settings.
Quickly looking at some of my gear
1176 - No
LA2A clone - No
DBX 165a - No
Shure SE-30 mic/compressor - No
Art VLA Compressor (used for crushing audio into tube distortion) - No
Moog Moogerfooger Chain - Yes
Guitar pedal chain - No
Chameleon Labs 7802 (used for crushing audio into tube distortion) - No
Eventide H3000 - Yes (but annoying to get to via menus)
Yamaha SPX90 - Yes (but annoying to get to via menus)
Alesis Quadraverb - Yes (but annoying to get to via menus)
Reamping to a Guitar Amp - No
Sanamp - No
Strymon Bluesky - Yes
For the most part alot of newer reverbs and things have wet/dry settings, yes I agree.
However reverbs/fx from the 80’s have really annoying menus to deal with. I honestly think when Logic X added the mix/wet knob I started using my H3000 alot more.
Compressors always usually don’t have mix/wet knobs (for the parallel compression trick)… unless they are of one of the few modern thinking ones that have it.
And for things like distortion (running things though guitar pedals, or over-driving tube gear etc) usually this doesn’t have mix knob.
Just adding that one thing (mix knob) to the External FX plugin opens up such creative potential and workflow speed in a mix. Having group channels and FX sends all over the place for every track becomes a pain.
It would take a Cubase engineer like an hour to implement!