"All of this" vs "All of these"

I've read/heard people saying "all of this" and "all of these" where this and these both refer to some plural entity. Are there any differences in using this and these in this way?

I'm guessing that the answer is that it doesn't matter, but wanted to make sure.

For example (taken from here)

Participants commonly report increased mental clarity, improved quality of sleep, higher energy levels, and better moods. You can achieve all of this WITHOUT ...

Shouldn't it be "You can achieve all of these"?

Solution 1:

In the context of your question, "all this" means many things taken as a single whole. "All these" means many things as part of the whole; not everything.

For example I might be a boss pointing to a room full of boxes and say, "all of this needs to be moved into the next room." I can use the word 'this" because I mean everything. It is taken as a whole.

If I meant only some of the boxes, or if a mistake could be made if I'm not specific, I would point to specific boxes I wanted moved and say, "all of these need to be moved into the next room."

Another example I can think of is something I can picture from the movies: a rich guy looking out at all the land he owns with his son beside him. He waves his arm and says, "one day all this will belong to you." He means everything. The whole. Even if all his land is made up of individual items he would not say, "all these will be yours." It might be correct, but it also implies he is only talking about certain parts of the things in front of him. The son would ask, "which of these will be mine?"

Solution 2:

Another distinction between all of this and all of these may turn on whether the all consists of material that is likely to be individually enumerated or taken as an uncounted mass.

The lot was filled with ping-pong balls. The owner said, "Take all of this to the dump."

In contrast:

The lot was filled with old cars. The owner said, "Take all of these to the dump."

While the ping-pong balls could be counted, they are insignificant enough to deal with as a collective mass. The cars, less so.