they just mechanized everything, favour high-yield varieties (but imo tasteless, also a consequence of cultivating loose sandy soils where mechanization is easier)
It is a combination of many factors
We have around 500 potato varieties in NL of which around 50 in commercial farming for food. The other for industry or people having their own little vegetable garden. Tradition. I like most the (clay) potatoes of an ex-inlaw sister. Still get now and then some
Last year 80% of the harvest was from clay soils, 20% from sandy soil. NL is a river delta with much river clay and sea clay. The sea clay from sea polders. It was a dry summer.
When there is too much rain the clay farmers whine because of smaller harvest (potatoes rotting in the ground and ground to weak for mechanised harvestibg).
When there is too little rain the sandy farmers whine because the potatoes grow not big enough.
Yield was last year on average 52 tonnes per hectare. EU average somewhere 30-35 tonnes per hectare.
Now... all those varieties.
We have the Wageningen university. And from the traumas of lack of food of both WW1 and WW2 already after WW1 poldering actions were taken incl Wagening as expertise centre for higher yields. After WW2 this got again a boost of subsidies.
We talk about meanwhile 100 years of national top three priority knowledge expansion on crops cultivation. Wageningen university started in the 19th century as school for farmers and this is still strongly connected. Not an ivory tower university but a centre for regional farmer schools to train 16 year old kids into becoming a knowledgable farmer. Lots of feedbacks between regional farmer associations and "scientists". An uncle of me, with a big farm in a new polder, did nothing else than trials for newly cultivated potatoes.
And that still goes on. Like potatoes that do well in salty watered soils.
Now... that all these new varieties have no taste.... this is already history for obvious commercial reasons. Potatoes have nowadays to compete with rice, pizzas, spaghetti, etc etc. Consumers are also richer than in the 60ies. They want more taste.
And... there is no intrinsic reason why high yielding varieties should have less taste.
Potatoes I buy now insupermarkets are relatively to my youth:
cheaper
taste better
have thinner peel (so thin that I usually eat them including peel and only remove the peel after cooking for some dishes like with asperges etc)
are washed instead of having a second peel of clay when you buy them
and gadgets like purple potatoes, the same substance and purple as from for example red cabbage. And many more now becoming popular. The old genes of the original potatoes of the Andes mountains getting a second life.
And then you have varieties optimised for differing soils, for french fries, for potato starch, for wallpaper glue, etc, etc. And yes ofcyou optimise as well for harvesting techs, for all kinds of pests.
Potatoes is just another field of knowledge.
And what we buy with our wallet is meanwhile determining what gets developed.
Also consumer behaviour needs to emancipate... is emancipating.
The issue is the middleman corporate throwing up hurdles for good consumer emancipation and benefitting from that !
Shortcutting between knowledge and people desired indeed.