Wolfram's framework is unfalsifiable and contains no new explanatory power. That alone should be sufficient to show you why folks are so skeptical of the claims. Combined with the fact that he introduces new terminology and refuses peer review, this should give you reason to expect that there is a simpler, more canonical, already-explored branch of theoretical physics which covers the same stuff.
I wish that you had linked to the material that you didn't "get anywhere with"; without it, it's hard to actually examine the quality of the underlying arguments. I found writeups like [0] which seem extremely well-argued; the formal ideas come from [1], and the core idea is Bell's theorem [2]: there is some essential non-locality to QM, we can experimentally see it, and so we can't just say "oh, it's all a big computer", even if it's a computer with interestingly high dimensionality or interconnections, without further justification.
[0] https://www.singlelunch.com/2020/04/23/why-stephen-wolframs-...