Reasons for MCU "Vision" downfall

Reasons for MCU "Vision" downfall 

As more superstar are increasing in the MCU, there are some characters who are getting worsed by every movie.

Since the MCU characters As the number of characters cast by MCU is huge, some of them were bound to get less creation of characters than they deserved. One can argue that the less "real" characters were those who got short shrift, probably for good reason. Brands such as Hulk (Mark Ruffalo) and Vision (Paul Bettany) are good examples, based on heavy CGI use.
He's a character in the case of Perception, who didn't quite get the respect he should have had. He was definitely a character who might have gone wrong in being an Ultron-created android. Only Tony Stark (Robert Downey Jr.) putting into Vision his J.A.R.V.I.S. program prevented him from becoming a villain.
and MCU fan thinks that the character is wasted when he became the official member of the MCU, And in the upcoming let's hope, there will be a positive impression.

Was the main region for his character failure is after "Age of Ultron"?
According to fans because he didn't behave almost as violently. His battle scenes in Ultron's Age were definitely exciting, including using his phasers as starters to obliterate other Androids. people want him to see as a fighting machine but as his character shown in more movies he became more docile.
will he return in the upcoming movie "Wandavision"
and the answer is "yes"  in the marketing of WandaVision disney+ has said he will surely return in the movie.
After this is he will go back to his action seen again? 
Based on all of WandaVision's previews, it appears the show can be described almost impossible. No one speaks too much to keep the secrets all over.

One thing that some cast members have revealed is that it will start as a sitcom of the 1950s and then evolve into a regular MCU film. Apparently, this means some more typical big-screen action scenes than streaming. If this holds up, then that means Vision going back to its android appearance from a human "vision." However, how this works in the context of Marvel canon is likely up for a million fan board discussions.
Whether that means death for Vision was subjective is something else. Because Marvel deals with death as not irreversible, it's at least more explainable in the world of an android over of the very human Avenger.