In just three short lines, this poem sketches a person who is good at the wrong thing. The "he" in the poem can walk away from relationships, cut people off, and leave things in ruins, but he can't face the struggles inside his own head. The poem never says who he is, so he could be someone the speaker knows, or possibly the speaker themselves, judging by how bluntly the idea is put.
The two images do the heavy lifting. Burning bridges is something you do to other people, and it's quick and dramatic. Fighting personal demons is slower, private, and much harder. The line break after "better at" makes us pause on the word "better," which sounds like praise but turns out to be a quiet insult. The mood is dry, tired, and a little sad. There's no anger here, just the weary tone of someone who has watched the same pattern play out, and who sees that destroying connections is easier than facing what is really causing the trouble.