It’s always amusing how small the Justice League movie feels

To be fair, that's basically what JL was trying to do, starting with straight out callbacks to the cartoons ("Booyah"). I think it was deliberately scaled back *because* of how bombastic MoS and BvS (and even SS and the third act of WW) were criticized for being. The wanton destruction, collateral damage, blue lights in the sky, save-the-world stakes, etc, each time were overwhelming and tired by JL, and things were slowly being scaled back (re: "everything is abandoned and unpopulated!" in BvS) to the point that JL deliberately just focused on a single Russian family armed with Raid.

Of course, this is an idiotic way to do a franchise. You generally want the stakes to get bigger each time, but Snyder couldn't start small. He's Zack Snyder, so everything has to be big and crazy. He blew his Death of Superman load on only the second movie.