Canopies are made of fabric and degrade; they need maintenance and replacement, which isn't going to happen in America. Instead, they'll be put up once (at great expense, with some company profiting handsomely, and it just so happens that company is owned by the brother of someone important on the city council), and then just left there. After a few years, there will be holes in the canopy and it'll look like the movie "I Am Legend" (where the city degrades quickly because all the people are gone and no one's doing maintenance), and no one will want to play there. Parents will complain, but the city will push back because fixing it requires demolishing and rebuilding the entire playground, which is very expensive and not in the city's budget.
They're relatively cheap and easy to replace, having a neighbourhood play action committee can handle the costs every five years to a decade with regular bake sales.
What's more of an issue is
> Canopies are made of [ Plastic ] fabric
typically knitted polyethylene blend | woven polypropylene. The degradation of tens of thousands of kilometers of plastic shadecloth each year is a big source of microplastics in the environment .. which has been getting some bad press of late.
That is still a bargain for the services that the tree provides.
The best "premium shadow package" available on the market. Comprises: filtered light, relaxing breeze sounds, noise blocker, chirping birds and flowers, dumb squirrels frolicking around and fresh soil, all in the same package for just ten dollars a sapling.
$10 for a sapling is extremely cheap. That's more in the line of what you can expect to pay for a 2 year old seedling (ref: https://monroecd.org/tree-sale-2024/). But I agree. I've planted 10k+ seedlings (most not personally; I hired a crew). It's actually fun to watch them grow. Douglas Firs take about 5 years to grow to 5' (from 18"). After that, they grow 3'+ a year. Not being a food source, they don't attract wildlife though nor do they have flowers.