I’ve done more Eastern big woods whitetail than anything, so I’ll comment from the perspective. (Plenty of backcountry and Western posts already that I agree with.)
1. Layered clothing system for all temps and weather in appropriate camo if bowhunt. Sweat isn’t only a mountain thing.
2. Boots you can move in, that are warm to sit, or have overboots/warmers for sitting if late season.
3. An effective truck camp (tent, cot, bag, stove,food) suited to the season (wood stove + tent for rifle/muzzleloader)
4. Books, not magazine articles, on effective hunting techniques.
5. A reliable quality scope if firearm hunt
Every compound bow, arrow, rifle, slug gun, muzzleloader, ammo, binocular, daypack, chair, camo pattern, clothing brand, rangefinder, scent/control, call, rattle, clothes wash, etc etc, worked (or didn’t) without regard to its vintage, brand, technology level, or age. This stuff is all over hyped (yes including caliber, action, brand, weight, features of your rifle). I think all this is secondary, in the Eastern truck camp scenario, than my top five. I’ll illustrate.
Example. If I had to choose one new and one old setup to go hunting tomorrow, from this list:
1920’s hunting boots/clothes full kit
1920’s sporterized ‘03 Springfield w/peep
2022 boots and technical layered clothing (FL/Kuiu/Sitka etc) full setup
2022 Blaser R8 with Swaro scope
I’ll take the Springfield and Sitka every time.
Prove me wrong!