There actually is a pretty large community of hardware reverse engineers decapping chips for fun, sometimes just to dump internal ROMs (like in this case) and other times going as far as to try reconstructing the original schematics and netlists in order to document the chip's internals and allow for more accurate emulation, in some cases all the way down to the transistor level [1] [2]. If you want to learn more, Ken Shirriff has written a lot of blog posts on the subject [3] and Siliconprawn [4] hosts a huge collection of die shots from many contributors.
[1] https://floooh.github.io/visual6502remix
[2] https://github.com/iaddis/metalnes
[3] https://www.righto.com/
[4] https://siliconprawn.org/