Planted tomatoes "like in the textbook", but they got sick and produced three tomatoes?
The whole point is that the distance between bushes depends not only on the variety.
For example, indeterminate tomatoes that grow upward require 60–70 cm between holes. But standard bushes with a compact root system will get along at 40 cm.

But there is a nuance: if you grow them in a greenhouse, add another 10 cm - high humidity provokes fungus.
For open ground in southern regions, on the contrary, plant more densely - this way the foliage will protect the fruits from the scorching sun.
Another secret is the orientation of the rows. Place them from north to south so that each bush receives an equal amount of light.
And never ignore the wind: in windy areas, reduce the distance by 15% so that the plants support each other.
In two months, you will see how correctly planted tomatoes will turn into a jungle with dozens of juicy fruits.
And if the soil is poor, increase the distance between the bushes - the roots need more space to find nutrition. In fertile black soil, on the contrary, you can save space.
For tall tomatoes, use trellises: tie up the stems as they grow so that they do not shade their neighbors.
And remember: dense planting is a paradise for late blight. If the leaves start to turn yellow, thin out the bushes by removing the lower shoots.
Interesting: tomatoes planted next to basil are less likely to get sick. The aroma of greenery repels pests and improves the taste of the fruit. In a season, you will harvest a crop that will not fit in a bucket.