Those companies at at the top all still have competition who need to buy the same supplies, so they aren't monopsonies, but they're close enough that this is an opportunity to use the word 'monopsony'.
Are these things true or equivalent? These areas are not necessarily booming. They are stable with few consumers of the goods.
At this point, every scheming hustler is in the market for a bit coin miner. Same in a gold rush -- any fool can dig with a shovel. It's not until boredom or consolidation happens that the shovel maker margins start getting thinner.
Better is to think of it as making something a lot of people want. Lots of miners = lots of people who want shovels/ASICs. Whereas mature industries like those end up as monopsonies i.e. a single buyer with lots of suppliers.
In most of those cases the guys higher up the food chain have appreciating assets such as land, consumer brand value, mining rights, developed oil fields and mines, etc. The guys lower down the food chain make depreciating assets and have to get up every morning and make new stuff to sell every day or they go out of business.
In this case, the shovel seller is believed to use the shovels a bit before selling them. In that way, they extract all the value from the shovels themselves, before a purchaser ever digs.
