Having been a mobile engineer for a lot of years there are, in my opinion, many so called "improvements" which have, and are, detrimental to caravanning, and add extra unnecessary cost to the owner.
First are the One Shot hub nuts.
The old system of castellated nuts and split pins was a low cost but very good system and allowed for wear to be adjusted out and apart from a bit of grease (and a lot of paper towelling to clean off old grease) was a much superior system with no ridiculous charges for the nuts (which should not be charged as extras as the service cannot be done without replacing them).
Then the fixed bulkhead regulator.
The old style cylinder mounted unit was (and is) a single stage regulator which worked very well for a long time.
Ok, it let the oily substance we all know about into the pipework but it took years to present itself as a problem, unlike the bulkhead regulator which I have changed hundreds of due to blocking, and at considerable cost to the van owners.
Then there is the multitude of electronically controlled items from fridges to heating systems which are far too complicated and sensitive to be dragged around over bumpy roads for miles and miles.
Simple controls are much better on the bank balance.
Do you "really" need to control the heating etc from your smartphone? or have the heating so minutely controlled every second of the day and night? or have a fridge decide what fuel source is used? Do you "really" need a red light to tell you when the cassette is full?
On a personal note I think that people actually want to transport all the high tech stuff they have at home, despite it being subjected to stresses and strains that it is not supposed to be, like vastly changing temperatures, damp air conditions and vibration.
I think that a lot of people rely far too much on being told what to do by electronics and have lost the ability to do simple things.
Some things are a good improvement, such as the stabilising hitch head and ATC but that is a small number.