I have to concur with this. I tried the Impossible polaroid film a few years ago and it's not very good compared to the original polaroid film and the Instax film.
I use the Instax mini now and it's a great little instant camera.
I myself think that the colors of the Instax line are fantastic, but if you want a larger image, Polaroid is yet again the place to go.
Polaroid runs about 2USD a picture (being 8 pictures by cartridge).
Instax Wide, by its B&H price, is around 0.9USD a picture.
I think Polaroid image size is 3.1 by 3.1 inches
Instax wide is 3.9 by 2.4 inches
Instax Mini film can be bought in a ludicrous number of physical retailers (considering the overwhelming ubiquity of digital photography now) - Target, Michaels, Urban Outfitters etc. Instax Wide not so much, another indicator of it’s increasingly niche little market.
I have the latest Fuji Instax Wide model given to me as a gift and it’s really not difficult to see why Mini is so much more popular - it’s significantly more expensive and much bulkier than the cute little mini models. I used it three times and then left it in a cupboard, it’s simply too large to carry around regularly.
Finally I’d argue the difference between 3.1 inches of image height on a Polaroid and the 2.4 of the Instax Wide feels much more different in person than the numbers alone might suggest. For me personally, I don’t think it’s a nice substitute for the look and feel of the traditional Poloroid format.