My plants get far larger and look healthier than anyone else I know or see; however, I get small, few or no vegetables off of them except for tomatoes. For example, I planted 8 watermelon plants and had almost 30 watermelons, none got big enough to use. Out of over 150 ft of pumpkin plants, not one pumpkin. Huge acorn squash plants only two of them, bell peppers few and small, though some plants three feet high and look very healthy. I must have pollinators since I have an abundance of tomatoes so have no idea why.
Vegtable Garden Growth
Certified GKH Gardening Expert
It is likely an issue with fertilizer, as it sounds like your plants have abundant growth with little flowering or fruit yield. This is oftentimes due to too much nitrogen in the soil, which leads to lots of healthy foliage growth but little else. Try to limite the nitrogen and offset it with some phosphorus, like bone meal, to help promote more blooming and fruit production. Here is more information: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/phosphorus-plant-growth.htm