From Chicago, with that much time you can get to Yellowstone and back, with stops for Mount Rushmore and Devil's Tower. You could have time to visit Glacier, or you could go to the Grand Tetons. All of your visits will be relatively short (many go to Yellowstone for a week or two, year after year, it is that big).
Or you could go to the Grand Canyon, by way of southern Colorado towards the Moab parks complex, then down through Monument Valley to either North or South Rim, then likely coming back via the highways that replaced Route 66, with much to visit going both ways. Alternative to the Moab parks and Monument Valley might be Bryce, and Zion, particularly if going to the north rim of Grand Canyon.
I've managed each of these trips in a two-week time frame, from SE Michigan, a half day out of Chicago. While living in the middle of the plains now cuts two-three days of driving time, it can still be a problem connecting all the dots further west.
Putting Yellowstone and the Grand Canyon into a two-week trip from the Midwest or the East is probably feasible in terms of driving time, but leaves little time to visit either (a day each for GC and Yellowstone?) and means you will have to drive by a lot of other interesting places that are on most folks "out west" bucket lists.
There are escorted tour that do what you are talking about, but they usually fly to and from Wyoming, Colorado, Utah or Nevada, and have a team of bus drivers moving you from place to place for 2-4 hour visits at the big stops, less than two hours at the "lesser" national parks or monuments. Sometimes the tour use air connections rather than long days of road travel for the big moves (like Yellowstone to Grand Canyon).
But these are "bucket list" visits, checking of as many "been there" as possible, even if you were inside the park gate for maybe no more than an hour. I remember my first visit to Arches was 45 minute sidetrack on the way to supper, and skipping through Colorado NM in about 90 minutes enroute from Grand Junction to Green River. So how many "out west" places you can visit in a given time depends on how long you plan to be there, in addition to how long it takes to get place to place.
Yosemite is out of the question for two weeks from the East or Midwest, visiting anything else, as it is just that much further, at least a full driving day from Las Vegas if the routes from the east are open. Most visitors from GC will go into Southern California, then up through the Central Valley, to approach from the west, rather than trying to get over the Sierra Nevada from the east.
I've done some of those escorted tours too, other places in the U.S. and in other countries, but will not do it "out west" because I want more time in most of the parks. I might take someone's western tour plan and use my RV to turn their 8-14 day tour into a 30 day tour for me.