I mean, ignoring the seemingly-condescending tone of the remark, let's go over the logical facts behind the 3 houses.
A Miner's house has a drill you spend nothing but labor on that replenishes when you use it. Sure, you can buy a drill for vocation, but that's spending a form of currency for something the house has for free.
A Rancher's house has a pen you spend labor and the cost of the animals and the animals don't die. Sure, you can buy/make pens, but that's spending gold for something the house has for free.
A Harvester's house has one extra seed bed. All 3 of the houses already have two seed beds, so you're working on a house that has nothing unique to offer that the others don't. Ooh la la, one more seed bed instead of me having to plant bundles or single-plant 50 seeds, WHAT A BARGAIN.
And looking further into your complaint, just how new are YOU to the game? Crafting houses (Armorer's/Apothecary's/Trader's) have Complex Processing Shelves that process crafting materials related to metal, lumber, stone, cloth, and leather. Multipurpose Trimmers on upgraded Thatched Farmhouses are for Husbandry, Farming, and Gathering. Two entirely separate things for each type of house that make the two different house types unique on their own (a crafting house of various things vs a house to live in that can grow various things). Your suggestion to make the benches separate from the buildings makes the buildings that own them not-unique and would make them not worth as much considering how other house types can't do the same thing.