Hawaii and even islands as far as Easter Island were settled by sea faring peoples. Why is the "ice bridge" hypothesis always the go-to explanation for how the Americas were settled when these sea faring people could have easily settled in Central and South America? I also ask this because the Central Americans had more developed stone working and building skills as they had built large pyramids whereas the North American natives primarily were mound builders as if their architectural expertise devolved.
North American natives primarily were mound builders as if their architectural expertise devolved.
I want to take a moment to address this line of thinking as its a poorer approach to understanding pre-columbian cultures. Comparing a mesoamerican pyramid to an Woodland period Effigy Mound along the upper Mississippi is like comparing apples to orange juice. They not only come from different cultures but almost certainly were constructed for very different reasons by very different communities. You're coming at it from a unilinear line of thinking, there was no devolving that occurred. Simply just people building whatever worked best for them. A great example is Monk's Mound at Cahokia. What may appear as a mound of dirt is actually a carefully constructed series of layers designed to help the mound withstand the elements all while still being built to fit the larger grid at Cahokia. Clays would have been used and layered to allow for water to drain without damaging the mound through erosion. The construction of mounds was far from simple and would have taken a tremendous amount of man power and planning. Interestingly, the plaza surrounding Monk's Mound is estimated to have taken the same amount of manpower to construct as the mound itself. This was all done by hand using baskets, and resulted in a massive plaza that was almost perfectly level.
It's also theorized that many of the mounds at Cahokia would have locations chosen not only due to astronomical events but also tying in seasonal flooding to create a more powerful image. Basically they had a mound that not only fit with a specific lunar event, but that would also tie into flooding that occurred in that portion of the city. Again this is all while keeping these constructions to fit the larger grid utilized at Cahokia.
Mound building is not simply "devolved" pyramid building. It is its own form of expression practiced at a level of precision we can barely replicate today.
Edit: also I want to apologize to OP if I came across as calling them out on this, I do not think you meant anything by it and can understand how you came to your line of thinking on this
It does seem that Polynesians reached the Americas at some point before Columbus -- this older thread goes into some detail on this -- but the time of contact would have been well into the Common Era; the Americas were settled at least 17,000-14,000 years before the present, which makes diffusion from Polynesia an interesting but flawed hypothesis. For more on this, the FAQ section of our sister subreddit /r/AskAnthropology is useful.
This has been proposed before with the most notable example being Thor Heyerdahl but most of the consensus rejects this. See the comment linked above by u/l33t_sas for a great explanation from a linguistic perspective.
Edit: I misread the OP so please see replies