Canon's television advertising slogan, "So advanced it's simple!" is what really started the 35mm SLR and autowinder "revolution". The AE-1 became like the best-selling 35mm film SLR of all time in a few short years, based on good results obtained simply...as in with almost no user intervention, no user "skill". After the camera makers sold a lot of 35mm film SLRs from the mid-1970's until the late 1980's, they looked around for the next big thing that would be a distruptive technology,and would allow them to sell all-new gear to their old existing customers. Autofocusing SLRs and all-in-one zoom lens compacts were the new next big thing, and they hit simulataneously.
Here's a case in point of how a specialized Scene m ode can outperform a camera's normal,everyday settings. Years ago, I sold a "baseball mom" a camera to take better pictures of her son playing baseball. She came back with some disappointing results...the chain-link backstop was in great focus. Uggg... I told her, "use the distant landscape mode, the "mountain symbol". SHe asked me how that would help, and I told her what I knew from having read the manufacturer's Selling Points Guide: specifically, that thecamera favors a HIGH shutter speed and FAVORS DISTANT targets, and tries to eliminate close-focusing priority tendencies. Why would that be? Well...the camera maker understood that for a DISTANT MOUNTAIN ICON, the success depends on 1) ignoring close-range interference such as typically caused by dirty airplane or train or car or tour bus windows 2) a FAST shutter speed, since many times these photos are taken from aircraft, tour buses, trains, and so on and 3) not accidentally OVER-exposing; over-exposure ruins distant landscapes pretty easily.
She came back the next time and got GOOD baseball pics by using a scene mode that basically featured 1) a built-in near-focus limiter that restricts the camera to DISTANCE-priority focus acquisition and 2) FAST shutter speed which combined with the wide aperture used limited the degree of in-focus of the close-in backstop chain links. That mode also worked well for zoo shots of caged animals, ignoring the strong patterns of close-in subjects.
One thing the "scene modes" do is to try very hard to ensure against what you might call "catastrophic blunders caused by stupid camera setting combos". You know, the realllllly serious mistakes, or grossly inappropriate permutations of exposure triangle that can result when a camera is set, well, for the polar opposite conditions. Scene modes really caught on back when I was selling cameras, with the introduction of the THEN-NEW "zoom cameras" like the Pentax IQ Zoom 90, then the IQ Zoom 120 and whatnot....basically the FIRST 28-90mm type all-in-one 35mm film cameras that used a powerful lithium battery that would last for YEARS if un-used, and could power a zoom, and a flash and a shutter and metering system and which were many peoples' introductions to a "carry camera" that was NOT their old AE-1 or their OLD Minolta SRT or whatever.
Moms and Dads and grandparents went nuts over these things. I sold a ton of them, 3,4 every day. They had scene modes because, well, the people buying them had a full-range camera and a wide-to-tele, and ZERO idea of what to do with it. These things had GOOD macro and macro flash! And 90mm telelphoto! Autofocus was only about 5 years old, and many people who had never been able to shoot a "good camera" were getting "a good camera". The scene modes really helped setting the camera, and autofocus did the focusing.
Advanced users of course will not need or want such "aids".