Multiple wives does not mean more lachatz (pressure). It means less – the husband can tell each wife that he is with the other wife, and then go back to work unhindered. (old joke, sorry)
ames, society is truly different than it was then. I’m not saying that women did not have the emotional needs that they do now. They certainly must have. But the fulfillment of those needs was not available through men. In general, society did not expect men to cater to the emotional needs of women the way it does now. That was true whether the man had one wife or four. Your expectations are based on today’s standards, which are quite different.
The Torah also does not demand that a husband fulfill his wife’s emotional needs to the extent that you expect based on today’s standards. It varies by the man’s profession. For example, if the man is a seafarer and he has four wives, he may only see each of them once in two years (one visit per 6 months).
I don’t know what the facts are relating to men forced to remain bachelors. I would expect that it is not so and that those men who wanted to marry and survived to marriageable age (i.e. men of property or means who did not die in wars) were able to marry. (Of course, society may have considered a good portion of men unfit for marriage, i.e. ineligible bachelors, but that is a separate issue).
There is also the age gap factor. Here (as opposed to the agenda taken on recently) I will throw my support behind the theory that if men generally married women who were a full generation younger than they, there would be a significantly higher population of marriagable women than men. But I could not say if the chicken laid the egg or vice versa (so to speak). I do know that until not too long ago in certain areas of Europe men did not marry until around 40, to women in their 20’s. The lack of polygamy created certain man/woman mismatch issues.
As to why polygamy “made sense”, I would posit that since women truly had no place in public society, marriage was the only possibility of life for them. Why then should a girl remain in the home of her parents, where she is little more than a liability (she can help with household chores, but I imagine that her net worth was not positive) if she can marry a man who will see her as an asset? A man with 3 wives can still want another asset. So they got married young, and to the best man they could get. Very, very different today.
To answer why men wanted multiple wives, try to think as a man in a polygamist society. Multiple wives shows status. Multiple wives means a large progeny, or dynasty. Obviously, a man would want to marry as many women as he can.
I’m sorry if the values of previous generations bother you. But our values would probably bother them much more. Do we think of our children as a sign of status or do we think of Lexuses (Lexi?) – at least they valued people more than things.