Was about to say this. Though less useful, because Partiful doesn't require an app so can be used by anyone.
I wonder how much the network effect may be leveraged for apps like these, to the benefit or detriment of apps like Partiful in comparison with Invites.
I know Facebook's last useful feature appears to be events in many circles.
Grass is faster, meaning for any given shot over the net you have less time to respond. This encourages attacking behaviour.
Clay is slower, meaning even off fast, angled, difficult-to-reach shots the ball bounces higher and slower, meaning you have time to get to it, thus prolonging rallies and points.
But beyond that, it's not just that players choose to play more aggressive on grass - a given shot is more aggressive on grass.
This is why the serve is more powerful on grass - you open the point with a powerful shot, and on grass that's harder to return.
Anyone working in this field is likely to be aware how woeful current actuators and power sources can be in a machine designed solely for one purpose, let alone how they might be in a machine designed for every single purpose.
Evidently this is an opinion, and the argument - which you are, of course, free to disagree with - is that 'not seeing those things' implies a privilege from which you are benefiting, or an ability to ignore the fact there is injustice even if you aren't benefiting.
If you have a bit of damage on your front door, is it better for the person observing you as you walk through the door to point it out (hoping you fix it) or to not point it out (hoping you notice it yourself and fix it, or alternatively that whether you notice or not you choose not to fix it).
I do not think it is subject to debate that our front doors have damage, so the question is how to remove that damage in the short/long term.