50+ has to be weighed against the total volume of trees. If you have too many trees in a small space, none of them thrive. It can be valuable to actively thin the forest so that you have a smaller number of thriving trees rather than a larger number of struggling trees.

If someone planted 50+ trees that are a terrible fit for the lot, well that's a good reason to take them out too, hopefully with replacements.

Personally, I live on a large lot with hundreds of trees, and it would be easy to select 50 trees that would be reasonable to cut down, and you'd hardly notice. But the only large tree we cut down was a (non native) cottonwood planted near the house that had bifurcated and was likely to fall on the house in the foreseable future. When we thin the forest, it's mostly younger trees in thick growth that don't have room to grow well.