The goal of a profit-seeking entity is to maximize profit. That is achieved by becoming a monopoly. Competition is just the consequence of multiple entities trying to become a monopoly - there can be only one. This is the motive part of market economy. The energy source.
Now, monopolies are obviously bad for society. Therefore, markets are regulated to prevent monopolies. This turns the market into an engine. You have constant inflow of upstarts dreaming of riches, fighting each other out to reach the throne of a monopolist, only to be denied it by regulation, and eventually become broken and/or pushed out by the younger followers.
Or, via another analogy: the market economy is designed like a donkey chasing a carrot on a stick attached to the animal, while standing on a treadmill. Being surprised that monopoly is the goal of companies is like being surprised the donkey would chase the carrot.
Industries where direct competition is allowable do not suffer from these problems.
No, they suffer much worse. Haven't you noticed how all goods and services go to shit over the years? This is not an accident, this is competition optimizing out any quality it can get away with removing.
No. I can't think of anything I buy that I would want to go back in time with. The quality in my experience has only improved, often dramatically. Those who try to skimp on quality get destroyed by the competition. What are you referring to?
The only thing I can think of that you might be referring to – based on what I hear other say, not based on my own buying habits – is things like appliances where manufacturers have really dug deep into computerization so that they can enjoy the same legal moats other tech companies do. But what you are experiencing there is the lack of competition we spoke of earlier.