I haven't read the other responses so this might be a repeat, but ...
There are two different power differentials going on.
One post is about a gardener and someone who can afford to hire a gardener. These people have vastly different degrees of wealth, power, and (possibly) immigration/citizenship status.
The other post is about two people who live next door to each other. In terms of wealth and power, their status sounds pretty much equal.
I think we all have a responsibility to practice kindness and generosity no matter what the circumstances. Because we're all going to need kindness and generosity sometime down the road. But when the wealth and power differential is greater, the burden of kindness and generosity is greater too.