It's hard to guess at the issue without images of the symptoms. Can you please share some photos of the problems? Plant disease spread and severity can be highly weather-dependent, and some cultivars have better inherent resistance to certain diseases than others. Information about the site conditions can also help us to narrow-down potential causes of decline. For example, while this is not a scientifically-proven association, some gardeners report issues with tomato growth when they are located too close to a Black Walnut tree (from the juglone compound that they naturally produce. Could a walnut be nearby that has matured enough over the years to now be impacting the planting bed when it wasn't in prior years? Additional causes of tomato problems are included in the page linked above, in case you are able to match-up symptoms.

Miri

Thank you for getting back to me but I am afraid this is moot now as all the plants are dead or dying. As an FYI, the closest black walnut is 50 feet away in my neighbor's yard. In the 23 seasons I have planted tomatoes in this garden, I have never had a problem growing tomatoes except for the invasion of brown marmorated stink bugs.

Sorry to hear that the tomato crop was a failure this year. If the tree is mature, roots from the Black Walnut could very well be reaching 50-plus feet from the trunk, in case juglone is one of the issues stressing the plants. Were the plant's symptoms not on our Key to Common Problems of Tomatoes page? Overlapping issues is certainly possible as well, which sometimes makes diagnosis trickier as one symptom obscures or interferes with another.

We haven't received many questions lately about pollinator abundance (or not), though we do get a few every year. Lots of factors play into insect population sizes, including weather patterns, habitat quality and availability, insect-specific diseases, and predation. Growing a diverse mix of (ideally native) flowering plants will help to attract and retain pollinators plus other beneficial insects. Many yards don't have enough flowering plants to support them, or use a lot of non-native species that don't feed our specialist insects, so unfortunately it's not surprising that declines appear to be taking place. Pesticide use, if someone in the area has had mosquito spraying performed, can be another factor.

Hummingbirds raise young and focus on insect hunting for much of early summer, though by now, fledglings should be exploring and learning what flower resources exist in the area while adults get ready to migrate in about a month or so, so this is when feeders and flowers start seeing an uptick in visits.

Miri