Both your questions really are valid imho.
They are not absolutely necessary ( I enjoyed the standard bike just as much as my top end model) and BMW are arguably "milking us" with electronics that promise slightly more than they actually deliver.
It is a "grey " area....for sure ... Technology is changing so fast.
These modes certainly do save you faffing with a C spanner when you take a pillion. They do take account of differing road surfaces , and rider desires as he describes. Some actually adjust damping in just milliseconds. Useful to have the bike react to braking/cornering/acceleration.
They do make the BMW marketing man's job easy ...since he can promise so very much, as you witness in the video.
They do have some difference between soft/medium/hard (I forget the BMW terms) and its fun to be able to choose different settings for different parts of your journey.
Rain and Dynamic certainly are worthwhile throttle modes ... take a long test ride and draw your own conclusions?
However , at the moment , they don't deliver suspension perfection. Not yet ! And other vendors can achieve similar/better results with WP/Ohlins/Nitron/Wilbers/Marzochi/other tecnhology
ABS Pro ( imho) is worth having ... once in a lifetime you might , in contradiction of your training and instincts, grab a bunch of brake mid corner. (Maybe a slow flying pheasant hit you in your chest , its happened to me , or a young deer runs out ?) If..... it saves you ending up in a wheelchair would you consider it worthwhile? (The tech is compellingly fascinating too with a microscopic gyro sensing lean angles).
There will be lots of opinions on this , each to his own. Thank goodness BMW offer us a choice.