Everyone Regressed Except Me

All I can say is the logic in the first 3 chapters is nonexistant. The MC is from a famous mercenary force, yet is living in a shitty rundown apartment. at the store he buys a new machete because his old one is “getting dull.” a gate opens a goblins start flowing out, and one of the weapons people start using are chain saws. which are for some reason full of fuel. The soldiers that show up after a while are seemingly next to useless / poorly trained and mc just snatches one of their guns straight from their hands.

all it shows me is that author put next to no thought into the start of the plot, and I can’t expect much for the rest of the story.

just a bit of through and I can already come up with a better start while keeping most of the same points.
Start with mc in shitty appartment. continue with the orphan story.
get to the store and see the literal wall of machetes. remember merc days, and add in a reason why he has piss poor job opportunities after. maybe he pissed someone off.
instead of having him buy it and use it to cut bubble wrap, just buy the bubble wrap and have the gate spawn, or have him looking at the machetes when the gate spawns.
grab one and use it.
have people use something other than a chainsaw thats fueled for some odd reason.

for the soldiers instead of just showing them being shaky and saying they’re basically useless, show it. have them fight but too many of them can’t implement their training in actual battle. have at least 1 get killed and mc picks up the gun then takes out the rest of the goblins like an experienced veteran soldier.