Standard of living is also a lot higher now
This is one of the biggest factors. We forget that Jewish day schools were not the norm a couple of generations ago. People went to public school, and then went to Talmud Torah after. Education is a massive expense. We also have an ever growing cornucopia of kosher products which were previously unheard of, many of which have become staples in our homes. Even just the availability of kosher meat has changed our consumption habits, and not without a price.
Not specific to Jewish life, the standard of living in this country have risen, as well. To have a car isn't even a thought now, and many households have 2 or 3. That's without getting into leases, which were unheard of and are a major drain on long-term financial health. Appliances have also completely changed our budgets. Look around your house and you'll find staples we wouldn't think to live without, but that 40 years ago either didn't exist or were considered a luxury. Even the ones that did exist back then were much simpler, lasted longer, and weren't nearly as much of a stress on the wallet in terms of both initial expense and maintenance.
The list goes on...