(Figured it out; it’s because Shader Graph treats some values differently than the Lit shader does, eg a smoothness of 0.5 on the regular shader should be like 0.1 on the shader graph… now why it does that is a separate question, but it can be solved).
Looks like this issue is not present on the floor, as far as I can tell from the screenshots. Isn’t by any chance something wrong with wall’s normals?
And the solution was?
Basically, there’s something strange in the way that Shader Graph treats smoothness values. A value of about 0.1-0.15 in SG smoothness is roughly equivalent to about .5 in a basic Universal Lit (given the same metallic and normal). Might have something to do with sRGB/Linear where a texture is being treated as Linear by Shader Graph but sRGB by Universal/Lit.