I've never heard of Muon tomography till today but damn it's really cool, and I'm amazed it's both been around for so long (50s) and has such wide ranging applications:
Muon tomography or muography is a technique that uses cosmic ray muons to generate three-dimensional images of volumes using information contained in the Coulomb scattering of the muons. Since muons are much more deeply penetrating than X-rays, muon tomography can be used to image through much thicker material than x-ray based tomography such as CT scanning. The muon flux at the Earth's surface is such that a single muon passes through an area the size of a human hand per second.
You might want to check out GScan - https://gscan.eu/ who are commercialising muon tomography for wider uses. Be that for tax&customs, border patrol or analysing building constructions.
I entered the Great Pyramid back in the 1990s when you were still allowed to, and visited the central burial chamber, and suffering heatstroke lay down next to where the sarcophagus was to rest. A surreal experience.
The UnchartedX YouTube channel [1] has excellent in-depth analysis of possible tools and construction methods used for ancient megalithic structures, including the Great Pyramid. He hasn't released a video yet of the new discovery, but he's talked about the possibility of this chamber before it was officially confirmed.
I particularly like his video [2] on the scoop marks around a partially quarried obelisk, and how the evidence might point to the use of yet to be discovered machinery. Not crazy stuff like alien tech or electrical power tools, but advanced engineering. Perhaps some sort of circular saw or device on a crane.
Do you have a particular timestamp for the video you linked where he starts to actually cover the techniques he thinks were used? I'm thirteen minutes in and all he's done is ramble on about how academics are wrong and the so-called indoctrination video. I agree the pounding stone thing seems ridiculous, but he isn't building up my confidence on what he may propose.
Edit: After looking into this more elsewhere, the pounding method doesn't seem so ridiculous. Apparently, according to Reginald Engelbach's experiments with the pounding stones by hand, he estimated the excavation of the obelisk would have taken a little over 7 months. That seems reasonable.
Couple that with augmentations of the pounding stone method with wood pikes or even scaffolding and possibly heat, it seems plausible the scoops, which seem to be a misnomer, would be created by those pounding methods and workers working next to each other.
I think the ancient "missing" technology is simply patience.
I agree the evidence presented ironically made simple or extended pounding narratives more plausible. Especially since the alternative presented at the end is an "advanced civilization before the Egyptian dynasties". Self discredited as typical for youtube.
Would be interesting to hear more about "weakening with alkali" mentioned in the comments.
Muon tomography or muography is a technique that uses cosmic ray muons to generate three-dimensional images of volumes using information contained in the Coulomb scattering of the muons. Since muons are much more deeply penetrating than X-rays, muon tomography can be used to image through much thicker material than x-ray based tomography such as CT scanning. The muon flux at the Earth's surface is such that a single muon passes through an area the size of a human hand per second.
https://en.wikipedia.org/wiki/Muon_tomography