No, you actually can't.

Humans existed for 10s to 100s of thousands of years without text. or even words for that matter.

No, you cannot. Our abstract language abilities (especially the written word part) are a very thin layer on top of hundreds of millions of years of evolution in an information dense environment.

How do you reconcile this belief with the fact that we evolved from organisms that had no concept of text?

The human world model is based on physical sensors and actions. LLMs are based on our formal text communication. Very different!

Just yesterday I observed myself acting on an external stimulus without any internal words (this happens continuously, but it is hard to notice because we usually don't pay attention to how we do things): I sat in a waiting area of a cinema. A woman walked by and dropped her scarf without noticing. I automatically without thinking raised arm and pointer finger towards her, and when I had her attention pointed behind her. I did not have time to think even a single word while that happened.

Most of what we do does not involved any words or even just "symbols", not even internally. Instead, it is a neural signal from sensors into the brain, doing some loops, directly to muscle activation. Without going through the add-on complexity of language, or even "symbols".

Our word generator is not the core of our being, it is an add-on. When we generate words it's also very far from being a direct representation of internal state. Instead, we have to meander and iterate to come up with appropriate words for an internal state we are not even quite aware of. That's why artists came up with all kinds of experiments to better represent our internal state, because people always knew the words we produce don't represent it very well.

That is also how people always get into arguments about definitions. Because the words are secondary, and the further from the center of established meaning for some word you get the more the differences show between various people. (The best option is to drop insisting of words being the center of the universe, even just the human universe, and/or to choose words that have the subject of discussion more firmly in the center of their established use).

We are text generators in some areas, I don't doubt that. Just a few months ago I listened to some guy speaking to a small rally. I am certain that not a single sentence he said was of his own making, he was just using things he had read and parroted them (as a former East German, I know enough Marx/Engels/Lenin to recognize it). I don't want to single that person out, we all have those moments, when we speak about things we don't have any experiences with. We read text, and when prompted we regurgitate a version of it. In those moments we are probably closest to LLM output. When prompted, we cannot fall back on generating fresh text from our own actual experience, instead we keep using text we heard or read, with only very superficial understanding, and as soon as an actual expert shows up we become defensive and try to change the context frame.

You could, but you’d be missing a big part of the picture. Humans are also (at least) symbol manipulators.