I think the underside of bricks should look less dark, so it's closer to the brick's color.
I also think the square 'tubes' should be less high contrast, it draws a lot of attention to itself.
Attached are comparison images with (old)roblox and blockland, Though these comparisons aren't perfect due to lighting engine differences, I think they still show what I mean.
I realize the current texture might be realistic to irl lego, but frankly I don't think it looks good as a ceiling in a lego house either,
Lego doesn't have to deal with this, because people don't normally look at the ceiling of a lego house, because people generally look down on them from above, and are too small to fit inside of a lego model.
(also, the more shallow lego plates don't have this effect as significantly as the full lego bricks do)