Absolutely true. On gravity, why should we not entertain the possibility that all matter, as well as all space is expanding?

If such a property existed, then gravity would be simply the characteristic of all things to expand towards one another, until they touched, after which there would be a force between them, causing them to stick together, the way two or more baloons blowing up separately in space would do.

Bigger clumps of things stuck together would exert bigger forces on other things coming to touch together, and so on.

I’ve studied science, and science fiction, on and off all of life, and never heard any reason why this might not be the case.

If it was the truth, then there never was any big bang, the expansion has been there in all things forever, a property of space and matter.

Further, if it existed, what would happen, if the expansion of a group of expanding atoms near us were to be somehow interrupted, even for a tiny moment, they would surely suddenly disappear from our perception, but where then would they be?

In a different universe, maybe.