I suspect the new consumer grade lenses will be best in class in terms of sharpness compared with most any competitors consumer variable aperture lenses. The 18-55 is fairly sharp for aps-c, the 55-250 is extremely sharp for it's price. (It's not nicknamed the nifty-250 for nothing!) I suspect they will try to do the same with the RF consumer lenses, and the lure of having a either a fixed aperture, a faster lens, or both will be the reason why enthusiasts will want to upgrade later.
And don't discount those consumers who want more than their cell phones! There will still be a subset of users who want something better than a cell phone who will buy these cameras. They are not all enthusiasts about equipment, they are just enthusiastic about taking pictures. Some of them will even buy them simply because they will look more serious about taking pictures while traveling than a person with a cell phone. That market is still there, it's just much much smaller. Even if only 5-10% of the basic consumers who may have moved on to cell phones keep buying, that number is still very large - it was nearly a 100 million less than 10 years ago.