Crafting a dungeon-crawler in the world of Immortals Fenyx Rising is a great idea, but the dev team behind The Lost Gods DLC didn't meet that goal. They nailed the look but completely missed on the gameplay. As a result, The Lost Gods feels like a mishmash of ideas without mastering any of them.
When it comes right down to it, everything in Crackdown 3 is by-the-numbers game design, and the end result is not more than the sum of its parts. There are hints of good ideas in Crackdown 3, but the end product isn't worth the $60 purchase. Unless you're getting it free with your Game Pass subscription, you're better off downloading the original game (currently free for all) and playing that instead.
The Infinity War DLC is nothing more than a movie themed character pack and a quick, cash-in level. It's not worth picking up the base game just for the DLC. If you already own LEGO Marvel Super Heroes 2 and want the ability to play with these characters, then consider the DLC a character pack and go to town. But if you were hoping to jump into a full Infinity War level, or mess around in a LEGO level inspired by the movie, you're going to be disappointed.