The sonnet appears to tell about the life and death cycle of people, with the element of materialism involved.
The sonnet describes people who desire to reproduce with "we desire increase/," to pass on culture and customs "as the riper should by time decrease,/" There is an understanding that the younger generation learns from the older generation, or at least that is an assumed ideal that older people would hold. What the sonnet suggests that the new generation is disillusioned of the "old ways," that they find their way to the top, often at other people's expense. This can hold true of today's society, where good will is sometimes eclipsed by hopes for success.
In the middle of the sonnet, the tone grows darker to tell of this hunger for "more" of everything in sight. The sonnet tells of famines created "where abundance lies" as the individual moves to hoard it all. The younger generation seems to be described as selfish, only caring about itself and its own glory above other things and people. The sonnet could be describing of someone's humble orgins, that this individual could be dissatisfied with the humble life he or she was brought up in and has ambitions for greener pastures. These ambitions only serve to decrease the value of other people and things.
More accurately, since this was written in Shakespeare's time, this would apply mostly to the rich classes. This younger generation would have been brought up in a prosperous life, and have no regard to what could have been otherwise. So they would eat drink and be jolly without any limits set whatsoever. This can also apply to the lower classes with its woes, the quest for abundance being impossible to a level that it is destructive. This sonnet can relate to our times, as our society can be extremely materialistic where the belief is that one with the most toys, wins. What that part of society tells us is that this belief hardly guarantees happiness.