It really lacks a lot of features from the original Gmod Sandbox, and currently doesn't provide any meaningful community content to play with. I'm afraid it's not as flexible and "community-driven" as the original Sandbox. I really hope it gets worked on sufficiently further on, and is hopefully brought to the standards of it's predecessor. If it's meant to be Gmod 2, it's very bad at the moment.
Like, for example - it only has stock weaponry (which is really poor in quality tbh), and you cannot download any community weapons / SWEPS (as they are called in Gmod). Same goes to NPCs - you only have two stock characters, one hostile sausage and one neutral "scientist" sausage. That's it. And the community doesn't seem interested or hooked enough to make any new meaningful NPC additions to play with - most of the community library is just pure brainrot or proofs of concept.
This new S&box really lacks any meaningful content to pull you in, and without it, you don't have much incentive to play it, or to make any new content of your own. And even if you wanted - as it seems now - you're quite limited with what you can contribute to the local "workshop".