lot of farms used to have bins round my way but are gradually being superceded by sheds because of the ease factor, if the crop is dry enough it's tipped straight onto the floor of the big sheds with grooved floor ducting ,very quick & efficient no augers or conveyors & if the shed is partitioned into two for different crops then you only need one big fan to keep the grain aired as opposed to say three bins operating three fans . the other advantage of course is ease just 1/2 hr with a brush at the end & job done, shed cleared.
With bins you have to mess about moving augers ,latching & unlatching access panels & farting around with scavenger augers & still having to use the brush.
The combines are getting bigger & more efficient so having a tractor & trailer tipping into a auger pit for 1/2 hr is time consuming .
our climate is also a big factor here as well ,although bins are galvanised rust does appear & the grain will sweat from condensation if the bin isn't filled .
the shed can always be used for a different purpose if needed& can be seen as an investment whereas a purpose built bin is an expence to be justified & the current price of grain does not justify this.