Between the rock-head gear-freak and the naked aborigine stands the well prepared well educated renesaince man who isn't afraid to shed his ludite tendencies long enough to carry some tools that would be difficult to improvise and not so techno dependant that he can't start a fire with available materials. Seems folly to me to live within easy reach of a bunch of durable and helpful tools and to choose to walk from there into the wilderness naked or even close to naked. Might be an interesting adventure if you have a support crew ready to help but not the sort of thing that I would volunteer for. Given that I can (and do) carry a wide range of helpful technology in my pockets such that it will be with me if I am dropped from a plane into a jungle un expectedly, why wouldn't I?

Seems to me that it is undeniable that our ancient ancestors actually had full civilizations or at-least tribal communities with nothing more than god gave them at birth for technology. That being said, they did spend a bunch of their energy and time inventing technology, teaching it to their young and preserving it so it wouldn't have to be re-invented and, yes, carrying it everywhere! Iodine tablets and boulion cubes will be gone quickly but a wire snare may be used a few dozen times if you are lucky and that might buy time to fabricate solid fiber snares from the vegetation. A squirrrell may be butchered with your teeth but if you have a blade it might be easier and leave you more time to create that long-lasting hardwood & sinew bow that your primitive idols used instead of the glock or similar firearm. In any long term scenario we will revert to technologies that can be replenished in the wild (the bow instead of the glock) The issue here is whether, in absence of the tribe, you will survive long enough naked of all technology to create the first instances of the primitive technologies that our ancestors used. You will quickly need to generate some weapons such as snares and bows and slings or you will starve. You will quickly need to generate or find fire supplies, I believe the two options here are flint or permanent tended fire if you are anywhere where moisture is a concern friction fires will become something you don't want to bother with. So you need to find some clay and bake up a fire basket. Yes you could get along for a while with a hide and some moss for a fire pouch to carry the all important embers. Let's quickly rundown the difficulties.

No technologies because of-course our ancestors did it so why can't we.

First you need fire - friction fire is possibly the answer here Well you've got no pivot unless you stumble upon a bone from some other carnivores activites. You've got no cordage so you must improvise here but there should be some plaitable fiber nearby (now fire is not day 1 but day 2)

Second you need shelter - or do you? In a sub-tropical jungle you might not need that much. Get a large leaf and cower from the rain-storms for a while.

Then you need water - well the aboriginals just drink the water so that's what we'll do. Cross your fingers and hope that you aren't one of the aboriginals who die early from disentery - might work but it doesn't work for all of them and they grew up on the stuff.

Now for hunting - well insects are tasty as long as you know which aren't poisonous. These make up a large part of the diet of many jungle dwellers and they are easy to catch so no tools needed.

Now how about dealing with those cannibalistic aboriginals who just found you tresspassing on their favorite hunting grounds. Did you learn their language? Do you look sufficiently like them that you will convince them that you are a long lost cousin comming back from walk-about?

A pocket full of stuff including but not limited to, steel tools: knife, wire-saw, snare wire, p-38 (remember why cargo cults exist) sewing needle, fish-hooks, sparking rod flint, (or bic lighter which will still spark for months after the butane is gone) , a couple of Xacto blades (make great improvised spear points among other things), small tin to cook in, some reasonably strong plastic items such as a 1 liter coke bottle, a few zip-locks, some zip-ties, a few tens of feet of nylong twine or paracord, some reasonably strong fishing line or dental floss, some nylon thread and your tools problems are dealt with for a year or more depending upon your level of proficiency and ability to care for them. These are durable things that are not replaceable with field-expedients. You can replace them functionally but at a much lower level of usability. If your scenario is one of awaiting rescue indefinately with the possibility of a short term horizon then the other items such as a Photon or chem light, a power bar, some iodine tablets, a large trashbag or two start to make sense. If I can treat the water I find with iodine for the first day or two while I improvise something larger than my altoids tin for boiling water I will be safer than if I can't and who knows, perhaps the SAR team will arrive before I start boiling water in a birch-bark pot.