One of the names for Succot is חג האסיף, the Holiday of Gathering. This is because most Jews were farmers and by this time, they had gathered all of their crops. For this reason, it was also a very prosperous time for most Jews.
The message of Succot was to remind people not to get carried away with the temporary security that money can bring. There is a well known statement of the Rabbis that אין אדם מורד בהקב״ה אלא מתוך שביעה, that a person only rebels against Hashem when he is filled up. If all of his needs are met, he doesn’t feel that he needs Hashem.
Perhaps this is the problem in the Western world. People live in incredible affluence and comfort like no other period in our history. No wonder that so many have strayed from the path of Torah. Things are too comfortable. They don’t need to lean on G-d. They have everything they need.
Succot teaches that this is not true. We live a very temporary and fragile life. Hashem decides everything and in a moment, our lives can change dramatically for the good or for the bad. Our flimsy Succa with its shaky roof, gives us a week long reminder of the true reality of life.