Green space it ain't. It looks like a East German commercial plaza - before the wall fell.
Tear it up, replace the hard surface with grass. Course that would mean somehow or other preventing it from turning into a field of weeds, thanks to the ban on weed control. Where I lived before in lower Etobicoke, there was a brand new gorgeous park/playground, Dalesford Parkette. Within a few years of City neglect, plus the to be expected traffic of kids and families, the grass disappeared completely and only weeds and mud remain.
I'm not familiar w/that particular spot.
I will say this, it is possible to maintain nice grass w/o lots of pesticide.
However, pesticide or not, grass in small, well-used parks is often trouble.
It's a plant, and it needs aerated soil to do well. Too many people over top of it and you get compaction.
In a small space using a groundcover that clearly isn't meant for walking on is often a preferable way to soften the landscape.
Alternatively, one can use wood chips, but they do need to be topped up pretty much every year.
If one is going to invest in grass, then you need to do a few things properly. First, make sure heavy traffic is kept off it by making proper use of pathways of adequate width which follow logical 'desire lines' (where people actually want to get from and to).
Second, if you need to stop people from creating a desire line (beaten in path) for landscape/sports/programmatic reasons then you need to willfully obstruct that choice. (generally fences, though hedges/flower beds/armour stone may work depending on the situation) .
Third, the grass needs a maintenance program. That means, water, nutrients and aeration from time to time. Nature can supply the water in most cases, but irrigation works best as a bulwark against drought. Lawns need the right mix of nutrients and its specific and different from what flowers or shrubs may need. In an urban park, nature is unlikely to provide this, and even if the right mix of dung/leaves etc was on the lawn, in most cases, it would be removed, meaning human application is required.
Finally, the City tends to buy all the same kinds of sod.
Mostly, that's fine, but if you're trying to make grass grow in challenging conditions (abnormally dry/wet, shady, shallow soil etc.) then you need the appropriate kind of grass. This may mean resorting to seeding.