More like rocket Science ... I'm more inclined to go with...
What I wrote is actually basic level stuff for chain or belt power transmission, so is nowhere even near so called Rocket Science.
Arbitrarily seizing upon just one element as being the assumed single cause, is a flawed approach in terms of proper diagnostics.
Regardless, seeing as you intend to change both sprockets and the chain, and use decent stuff, you’ll likely be A OK.
Now a wee bit more for you and all re chain stretch.
One can have corroded pins and/or spalled pins, and/or worn pins, any or all of which cause bushing I D wear.
This would typically be associated with the lack of, and/or the loss or breakdown of, the pin/bushing lubricant.
One could also have some random side plate yield along the length, noting this would normally be associated with abusive high grip drag starts in particular by low grade chain.
Last, care and use of a chain is far more important than chain size and grade, as long as the size and grade is suitable for the actual use.