Some thoughts . . .
Lower sulphur fuels will be driven by air quality concerns as they might relate to engine fuels, especially diesels. Nothing political there as those things are already happening in some states and will soon be nationwide.
Engine flushes, as administered by some oil change operatives (dealership or private shop or chain), are more profit-center-oriented than not. Not to mention their selling cost compared to a regular oil change. Many of the aftermarket chemical companies that sell the multitude of flush kits to oil change operations (dealerships and others) usually pay spiffs to the techs and service writers, so you know they are going to try to sell them when they feel they can. These are my observations.
With the positive AutoRX comments and postings in here, perhaps flushes are more needed in some cases than others. I like to look inside of the oil filler cap's openning and see "metal" rather than "coverings" too. I also realize that a good flush does not really happen immediately when the flush product is put into the engine's oil (as some consumers might suspect).
One one used car I bought years ago, I got the oil changed and then added a pint of Stewart-Warner Alemite CD-2 oil detergent when it got a quart low. When it hit a quart low again, it got another pint. When it got a quart down again, it got an oil change with a long drain period. Seemed to work well.
In later years, I started doing my own oil changes. I also started pouring a quart of oil into the oil filler hole while the drain plug was still out, trying to get any residual oil out of the oil pan. I figured that extra quart of oil was a little extra cost to pay for getting a more complete oil change (using normal oil at the time). But I could have put that money into an "engine rebuild fund" too, but we all know what can happen with surplus money laying around.
Enjoy!
CBODY67