There are a lot of things our Rabbonim may or may not have had. Many were poverty stricken. There is no gashmius in having cool air in the summer and heat in the winter (or should we advocate freezing to death as a GOOD thing?) Hashem put us in this world to enjoy it, not suffer (as some religions believe). it is hard to enjoy anything in temperatures of 85+ degrees, not to mention focus on learning.
True negative gashmius (because gashmius in and of itself is not a bad thing – we have to eat to live, we have to reproduce the species, we have to sleep – these are all aspects of gashmius), involves getting a fancier car than you really need, a bigger house, just to impress, lots of furs and jewelry (one fur is a warm coat in the winter, three or four is overkill, literally).
Taking many vacations a year might come under that umbrella (depending on circumstances). It’s all in how you live your life the rest of the time. If I want to eat a piece of steak or salmon, that is fine. If I go out to fancy restaurants 6 days of the week, maybe that’s a bit much. Hashem did not order us to suffer. In speaking of the mitzvos he said V’chai bahem. When we go before Him after 120 years, He will want to know if we made use of the wonderful things He gives us. Part of those things, is giving us the knowledge of how to build machines that make our lives a little easier.