Lakewood and BP aren’t exactly the shtetles our ancestors grew up in either. Both “MO” (which cannot be singularly defined by one person for everybody because of the huge spectrum) and the “Chareidi” communities in America have, to varying degrees in various areas, been influenced by, and openly employ, modern society’s practices. For better and for worse.
In my opinion, the way I define the Modern Orthodoxy I practice, the “Modern” isn’t the ikkar; it just modifies the orthodoxy ONLY to the extent of acknowledging that the world we live in has changed, so the day to day APPLICATIONS of the ancient, immutable, all important Torah may have adjusted. The Torah and its values stay 100% the same. This has been a constant practice throughout history, for poskim and gedolei hador to apply the unchanging Torah to the modern realities and issues at hand – hence “Modern Orthodoxy”. For example, people don’t make their livings drawing water for the shtetle of all frum yidden anymore. They interact with all sorts of people, out of necessity, sometimes unaffiliated Jews, sometimes nonjews. MO recognizes the importance of making a kiddush Hashem with these people and emphasizes the kavod habrius aspect of these interactions. Hence, one may not be ignorant of social etiquette or “common knowledge”. Hence, MO would say once a woman in a business environment extends her hand for a handshake, you can meet her hand. (deadfish or not, you touch). Others rule not to do this… for obvious reasons.
The point is, MO (at least when you are keeping the “O”) to me, is not changing halacha chas veshalom, only modifying the emphasis in accordance with our necessity to interact with modern society.
I set the guidelines for myself as: get involved with “modern society” to the extent that it is necessary to make a parnassa and help me be megalleh yichud Hashem by making a greater kiddush Hashem among Jews and nonjews (which ramchal says is the point of creation- so I wouldn’t consider that a tier 2 compromise).