The idea is that the trees planted will provide benefits that far exceed the costs of pruning or sidewalk repair. These costs can also be minimized with proper species selection, though in my experience HOAs typically lack the expertise to make good decisions on that topic.

This study found that for every dollar spent on tree installation, maintenance, repairs, etc, $5 of public value was returned. Seems like a good investment! https://www.fs.usda.gov/psw/publications/mcpherson/psw_2016_mcpherson004.pdf

Unfortunately, the benefits of trees are often intangible and dispersed across the community, while the costs can be more immediately felt in some cases. Ideally, your town’s urban forestry program should bear these costs so that they can be more evenly distributed like the benefits, but the political environment in some areas does not always allow for enough budget.

Because the city requires it? 🤔

Worthwhile to learn for yourself even if you hire someone—bad pruning is ubiquitous in the tree care industry, even by so-called professionals. Keep in mind that trees don’t need pruning for their own sake. So before doing any pruning you want to have a clear goal in mind. A young tree that you can reach from the ground is easy enough for a layman to prune if you do your research. If it’s bigger I might hire someone but ask questions and ensure they have the proper certifications: ISA in the US.

https://en.m.wikipedia.org/wiki/Hardiness_zone

Plant things that are right in your zone instead of stuff from a more Northern zone, this way when zones shift they'll survive longer as they'll be one zone off.