Bernard,
I was never under the impression that film cameras were able to easily produce usable images. Where are you coming from? Film is a bygone era of inefficiency and great difficulty. Why hark back to it? The whole process was cumbersome, time-consuming and expensive. We're far beyond that, surely.
To generalize that film is cumbersome and time consuming, is not accurate for all photographic disciplines, or all parts of the photographic process.
I went fully digital almost a decade ago. Processing RAW images from sports events, where a few hundred images can amass (4 day event) is no fun, even with in-depth knowledge of the workflow. Digital image quality is fantastic but I preferred handing film over the counter to a pro lab as it was 'Photoshopped' by the film manufacturer and chemicals - in my case Fuji Velvia rated at 40 ISO was my choice of film. I also knew with experience how the final image looked with Velvia, rich and full of beautiful deep shadows - we can obviously replicate this look digitally.
The downside from running a library is scanning, the dust and scratch removal is a painstakingly laborious task. Bear in mind that commission shoots didn't require any scanning, or pre-press skills, as the film was handed over to the client for reproduction; in the case of editorial submissions duplicate slides were forwarded that were fast to copy and submit - approximately 30 minutes to copy the slides and once again the lab did the processing - allowing me to be getting on with other chores, or relaxing.
When shooting film, we (snappers), would get back to our hotel after a long day on the golf course, meeting up for a meal, and a drink, having walked, on average, 8 miles (At the 2000 Open Championship, at St Andrews, my pedometer recorded 11.4 miles), lugging a 600 F/4 (6.5 kilos in those days), sometime plus a 300 F/2.8; 70-200, and 17-35 lens, as you can imagine the restaurant meal was needed, a well deserved break, and relaxing time. Nowadays most of the photographers are still sat in the media tent meticulously captioning images, to specific standards for their employers, and transferring data, etc, until they get fed up and leave (often tidying-up and finishing tasks the next day). Those rare photographers still shooting film have polished off their main course by the time photographer's, who shoot digitally, leave the press centre, often not having completed all of their laptop chores.
Being sat a computer for several hours, even if taking breaks, is not my idea of fun for the routine tasks that it demands - not all tasks can be automated. Over the years metadata (IPTC and then XMP) have caused many problems between software vendors, and operating systems, causing keyword and captioning errors; I must have had to tidy-up the metadata on at least three occasions, on thousands of images, the time involved, regardless of saved templates and key-wording expertise, has on occasions driven me, almost, to despair. The benefit of image metadata captioning chores are the sales potential.
If someone developed an 400 ISO, 35mm film, with the much finer grain, and resolution, than Fuji Velvia 50 ISO, I might be just be tempted to buy some second hand F5's before E6 chemicals run dry - there again pigs might fly.