Your hinges are probably fine. It’s the screw bosses that the hinge screws screw into that have come free from the bottom case. Many laptops that have a plastic chassis have this problem. Lenovo advertised this laptop as having “reinforced hinges”, but there is no reinforcement to be found inside. Interesting! You can try using epoxy to repair the mounts in which the screw bosses reside, but I suggest getting a new bottom case.

As far as cost-cutting measures go, it's both interesting and strange that Apple kept the extra steel backplate riveted to the LCD that makes the screen more rigid for pressure sensing. You’d think Apple would manufacture the SE’s screen like the iPhone 6’s; with only a foil layer for the backlight. The iPhone 6S’s screen assembly was a fraction of a millimetre thicker than the 6’s, cutting the battery down from 1810 mAh to 1750 mAh.

Apple probably did the math and found that it was cheaper to leave the iPhone 8’s tooling as-is rather than redesigning to make the screen more like the iPhone 6. Raw material cost-wise though, surely two steel backplates costs more than one?