Removing a tree is generally not a happy thing to do but sometimes it must be done. If a tree is dying or dead obviously we need to remove before it becomes a hazard. Some trees are notorious for falling over after they reach a certain level of maturity, such as hackberries, chinaberries, Arizona ash, cottonwood, and others. It is very important to use a certified arborist to diagnose this necessity so as to avoid unnecessary removal, as well check with multiple arborists and get different opinions.
reducing fire hazard
There are other reasons for tree removal as well, such as fire hazards, selective thinning, views, and building. With the wild fires we have had in Texas, many people have become very concerned about their property. Removing some of the junipers (cedars) and other underbrush can reduce this risk. You may choose to selectively thin your trees. This means removing a few trees. You might do this if there are so many trees that it is creating competition for their survival.
thinning for water conservation
Another reason you might selectively thin is to reduce the amounts of junipers (cedars) on your property or around a tree so stop the massive water intake from the junipers and provide more water for the more favored trees.
Finally you may need to remove a tree if it is in the way of a view or a new construction that is going up.
In any of these cases, you want to make sure that this process is being done in a safe and efficient manner. Removing a tree is very different from pruning one and can be much more dangerous. It is important that the person doing this work has the proper equipment, experience, and knowledge to get this job done.