To be honest I kind of look at skateparks right now as being "skate at your own risk" regarding covid.
I live in NYC. Parks get crowded, skate or not, and I think generally people are feeling more joy and contentment being outside, and it seems to not be adversely affecting the public to a terrible degree.
I would skate with a mask on when, statistically, we were spiking a lot, but through the 90-100 degree heat it really isn't any fun to do that. I'd rather stay physically inactive, thus I skate without a mask as do 95 percent of the other people who are skating. I take my own measures to stay away from people but in a city like this it's nearly impossible.
I'll be singing another tune when I get hella sick, but as far as the great outdoors are concerned, I wear a mask in condensed public spaces where people may not consent to me being maskless, like a very crowded street or something like that. When I'm at the skatepark I just cant do it. Everyone signed their consent away when they step foot inside to skate, in my view.
If I lived with my parents or was in close contact with people who are statistically more susceptible to great harm, I'd be taking more precautions, but luckily for me that's not the case.
On a side note, I did get a free covid test here, and the results took 15 days to come back (negative). Its very hard to be responsible if you're asymptomatic considering the speed of the tests.