Oh my, it seems like every site has a horror show. This poor Acer has very little room for its roots, no access to rain water other than splash, it's desperately reaching for sunlight so it can feed itself and the surrounding pavement most likely heats up in summer; it sports many stubs from poor pruning cuts.
Planted in the wrong place, the tree is hanging on. This is a common problem: people fail to consider the mature size of trees before planting. Shade-loving shrubs might be better here.
Vas Sladek, B.Sc., CLHT