First, I would take a walk around the area and see if I saw the expected bees working flowers. I would think it unusual if I never saw any bees where there were a lot of flowers. Bees can forage out for a very long distance and direct other members of the colony to what they find. And colors are there targets. (We can't wear bright clothing around the ancient oak tree beside the house because they attract the bees living in it. Even my orange Kabota tractor brings them in to check it.)
I guess I would try to find out if anyone else of the condo management is aggressive with pesticides. A lot of people simply don't understand the value of bees and that they have no reason to attack anything not threatening the colony.
As to birds, perhaps there is nothing in your garden to attract them. Usually, a bird feeder with food appropriate to the area will not go many days before birds find it. Doesn't have to be fancy. Mine is just a clay bottom pan from a flower pot. Although right now and right here (Central Texas), the birds who used to mob my feeder ignore it and find plenty of wild food. But a bird bath is always in season. So I have stopped feeding. They will only find more to eat as the fields around me produce corn and sorghum. They might well be still going for feeders where you are.
Read up on feeding birds in your area and be ready in the fall. Around here, I find black sunflower seed to be appreciated by all. Slightly messy, though. They throw the hulls around.
I can't say much about the vegetables, except that you may need to check up on the varieties and see that they are appropriate for your region. For instance, I can't get a lot of tomatoes to fruit. It simply gets too hot to soon for them to set. I have to find special heat tolerant varieties.
And you may need to fertilize or alter your fertilizer. Most places have state labs that will analyze soil for you and tell you how to amend it. And it might just be related to the lack of bees and butterflies. In order to set fruit, plants need to be pollinated. If you never see any sort of insect servicing your plants, that may well be the problem.
There are also plants specifically suited to attract butterflies. But most are migratory so will only be around parts of the year.
Also look up mason bees and the simple houses you can offer them. They are solitary bees and readily use houses that are collections of tubes or tubelike holes. They even try to use my scrap pile of irrigation tubing. They use the tubes to store pollen (which makes them good pollinators) and then lay an egg that will develop over the winter and emerge in spring. Very cheap and easy way to have bees living in your yard. Probably getting late for this year, but you can ask your area ag extension agent and be ready with houses next spring.
You can also feed hummingbirds, and that will help get them to notice your flowers and vegetable blooms.