system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU- Luke Cage] Where's SHIELD? Luke seems like something they would be all over.

So a big part of SHIELD's job is dealing with inhumans and people with powers, and Luke seems to be doing a shitty job of hiding.
gpt
SHIELD has had a dramatic few years between Hydra, inhumans, Ultron (for about 5 minutes) and, the biggest enemy of all, budget cuts. 

Because they've been so busy they can't follow up on every case. 

And yeah, Luke isn't exactly subtle but his power isn't super showy. It's easy for SHIELD to pass on looking further into him. With everything happening in there world, it's easy for someone to spot some dude carry 6 shopping bags of groceries at once and think they're powered.