Is that because nobody likes to, or because pressures for employers and economic conformity forces them? That this is "becoming less and less common" (implying it was indeed common) speaks to the latter.
Some people like it, because it lets you eat and take a short nap and rest, but then you have to go back to work, which is a pretty big downside.
However, we don't consider it a lunch break here, we consider it as having to work two shorter shifts per day.
That, in Greece and elsewhere where it happens, is usually a habit from an earlier era, when most city businesses were small and/or family owned, retail stores and the like, and people lived in neighborhoods next to their business. So they would just close the store, had lunch or a nap etc at the house, and come back open for business again at the afternoon.
The current situation is a regression, and not because of the remnants of the "3 hour break": commutes and/or major traffic, and offices that demand people stay late without major breaks, so you get the same 8-9pm to late shift, working constantly (and then having to commute back).
Only the regular course of modern business, is not to give back the lunch break time to family/friends, but for the companies to have you work 9 to 7 or 8 just without the break.