I have a number of reports for different audiences that use the same dataset. I now basically copy all the query steps to each of my .pbix files and let them exist independently. As you might imagine this becomes maintainance heavy whenever I makey any changes to it because I want them to remain in sync, which now requires me to go into all files in order to say add a column. Also this of course duplicates the data on the Power BI server.
My attemption fixes so far was to try and connect to an existing dataset using the Power BI Service, but I seem to lose the ability to change the format of the columns in dataset, for example I can't seem to add thousand separator. Secondly, I tried to set the correct format in the query process, which i also wasn't able to do, but maybe I missed something there. I figured maybe with dataflows it could be done, but don't think that solves it either as the connections seems the same as the way you connect to a dataset.
I have my Power BI files uploaded to an App Workspace, and I've tried to do exactly what you suggest. The problem I run into is that when I connect to this dataset I cannot change the formatting e.g. have numbers displayed with a thousand seperator. The 'modeling' portion of Power BI desktop is greyed out when connecting directly to a dataset.