With the moves away from Classic 'British" breeds of cattle, the American cattle industry changed a lot. For better or worse depends on your point of view. I grew up around Hereford and Angus which did really well on Oklahoma grass and wheat pasture. They tasted yummy with excellent marbling too!
The 'new exotic' breeds that were introduced grew to slaughter weight faster on less feed so, economics along with changing diet trends away from fat spelled doom for the cattle I grew up with. Personally, a 'black baldy' steer (Hereford and Angus cross) is what I want in my freezer still today, cardiologist and dietician approved or not (I'll take butter on my breakfast biscuit too!).
Marketing and advertising have had the biggest effect on moving family farms to industrial production methods, for better or worse. Beef, pork, and chicken are very affordable to all cross sections of society compared to times of the past. This also means production is now swayed by 'bean counters' in the office and the individual ranchers that used to raise your meat now have basically no say in what is done.
Prophylactic use of massive quantities of antibiotics in industrial meat production should be a concern of everyone IMHO. This is a public health threat that while not materialized yet in the human population at large, is a real potential risk to everyone.
As to side effects, all you have to do is look at what beef raised with artificial growth hormones does to some Cuban immigrant girls who reached puberty at a very young age. While this never was a personal concern of mine, industrial agriculture is putting some people at risk with large scale production methods that may work well in a high pressure over crowded industrial production facility destined for Wall Street stock values and dividends, it puts other parts of society at risk.
Having had the good fortune to spend significant time in Europe, I can confirm that food quality standards and laws in Europe as a whole are much tougher than in the USA. Food to me is much tastier on average, being 'field ripened' more often with farm animals being produced in more 'natural' ways, however, this does come with an increased cost to the consumer.
On a personal note, I'm still sad every time I eat a beautiful red Strawberry that has absolutely no flavor in the USA.
In the USA, it is a mindset that is often hard to overcome. My mother who gets at least three meals from one ~14oz steak scours the meat counter for the cheapest and leanest one she can find because 'it is a better value"! She would never pay $2 extra for one with some marbling. My sister is the same way with 90/10 flavorless beef in a 'chub'. :tsk:
Don't get me ranting about visually perfect vegetables and fruit that taste like cardboard in the USA versus superficially cosmetically imperfect ones in Europe that really have a nice ripe natural flavor. Just imagine a Strawberry without table sugar that tastes like a real strawberry with natural sweetness! Tomatoes ... at least in the USA you can still find "Heirlooms" grown by elderly people at home and small rural farmers at the local farmers market