As a woodworker I would love to grab a goalpost and drag it 30 meters further down the field - pine is not wood, pine is an organic cardboard with superior strength and durability to cardboard, but is otherwise the same material.

(You did make your point though. I just really vehemently dislike pine as a building material for furniture)

The problem there is figuratively with the posts. Screwing a board to a metal U is easy. Nicely joining 4 wooden legs to the board is not... I have also done the former multiple times, with custom-made lower parts and it is very painful to see highpriced cr* like the one in the link popping up everywhere, where it could easily be made custom (even in relatively High-CoL locations) for nearly the same price. The thing above is 30€ for steel, 2h of manual work (where the non welding prep of sawing metal pieces can be done by anyone... I did this for a trapezoidal shape of my own design...), next to nothing for painting (powdercoat would be nice, but likely not done...) and then a plank of some random wood from Ukraine (30€, 200€ if you construct it custommade from planks). I gather the main problem lies with the availability of designs and likely this could be solved by providing those (for example by an IT platform selling plans and matching suppliers with customers).