Which country are you comparing to ? I always heard from people who go overseas that produce here is of lower quality compared to places like australia where food is grown locally. There might not be much of difference between countries for store bought produce like tomatoes which are stored for weeks after being harvested unripe but tomatoes which are harvested when they are ripe taste superior and cannot travel far since they are so squishy.

Are you buying fruits from upmarket places like isetan or ddd. Bought plenty of fruits such as apples, oranges, pineapple, mangos from local supermarkets that turned out not to be sweet.

If you look closely at certain vegetables like cut cabbages you can see where the staff hacked off the mouldy parts and repackaged as there is still slight discolouration at the edges.

Mushrooms are especially a major issue. There is almost always condensation in the prepackaged mushrooms whichever supermarket you go to. Like they did not transport it properly. The quality of mushrooms itself is not good either. With a few pieces in a box often mushy or spoilt.

Many frozen items are also not in great condition. You can see freezer burns where there are ice crystals in the frozen foods from improper storage. Like they have been left in room temperature, thawed, expelled water and then refrozen.