Although this isn't a history question, but rather a "wealth transmission" question more aligned with social science, I can direct you towards a on a similar question I answered here and an Italy-specific answer here, although there certainly is much more room for discussion.

The short answer has already been given by Niccolò Machiavelli: "It is not titles who honor men, but men who honor titles." Having a title in and of itself is absolutely meaningless nowadays; however, those who do have titles often also have multigenerational wealth in the form of investments in business concerns, real estate, and not to mention strong social networks ("Men honor titles") that grease the wheels of the social ladder (or rather, the rungs? Poor metaphor). All these factors, and others that I'm certainly forgetting, allow them to continue to enjoy leisurely lifestyles to this day. That doesn't mean all titled aristocrats are rolling in cash, just that many of them are.