I distinctively remember customers in the mid-80's knew what software was available to the computer platform they chose to use. They used to base their choices on that.
Machine-readable data exchange was not as important as it is today, but market pressures would, probably, influence software writers to both write more portable software (in order to sell to larger markets) and to use interchangeable data formats (something educated customers would see as added value).
The whole idea of "major software vendors" would also be very different, as the market would be much more fragmented.
And no. We wouldn't be behind what we have today. We still have files in folders, windows and mice. The coolest OSs available today are flavors of Unix and a rehash of VMS with roots on a rehash of CP/M. Most Windows users still believe files must have a 3-letter suffix. Windows users still endure drive letters. Unix users frequently endure differences between local and remote files. Most computers have two processors and most programs can't figure out what to do with one of them.
No. We have had pretty little progress during this period. We had more of the same - faster boxes with more storage, more colors, more pixels and more GFLOPS doing more or less what we used to do in the mid-80's and 90's. It's really hard to imagine an environment that would result in even less progress.