I think you're the one with unrealistic expectations here. There's quite literally no way for you to install another OS with one click; even if you do have a device that allows you to flash other OSes to it, you have to unlock the bootloader and -- oops! That's your one click.
OP means it figuratively. Amazon's "one click" checkout isn't actually just one click, it's a metaphor for how simple they're going to make it for you to buy the item. Similarly, a "one click" install of another OS should be taken to mean "dead simple to install" instead. You're welcome to debate how easy it is to install Sailfish OS on those grounds, but if we're being pedantic then there's quite literally no solutions that actually fit the parent's description.
OP means it figuratively. Amazon's "one click" checkout isn't actually just one click, it's a metaphor for how simple they're going to make it for you to buy the item. Similarly, a "one click" install of another OS should be taken to mean "dead simple to install" instead. You're welcome to debate how easy it is to install Sailfish OS on those grounds, but if we're being pedantic then there's quite literally no solutions that actually fit the parent's description.