Not sure it has. I suspect they were not brewing super hoppy IPA’s over the last few hundred years and pretty sure if you jumped in a Time Machine and had a few beers from history I suspect you wouldn’t even recognise it as beer as we know it today and it probably wouldn’t have been too great compared to todays clinical and engineered beers.
As for open fermentation, again you’re not doing that for super hoppy IPA’s and the thick yeasty foam on top of the beer does protect the beer from oxygen, not to mention the open topped fermenter is located in a sterile clean room that is far more sterile than the dust coated and cobweb festooned garages and brew sheds most of us brew in. The beer is pulled from underneath and put into cask, though the process of going into cask is usually open to air which is why cask beer has a very short shelf life once tapped…precisely because of oxidation. So oxidation remains the enemy of all beers, but some styles more than others.
One aspect that has been mentioned before is repeatability. If that is important to you then you need every little element and detail of your kit, process and ingredients to be identical from brew to brew. So that is why the big breweries have the fancy pants stainless equipment and as a home brewer if you are after repeatability then the first place to look is the fermentation side of things.