I've had fairly senior roles so reading all the articles about how people can get screwed reminds me that I'm getting screwed, in a completely different way though and probably a lot more simple a way.
Depending on the position, you may also want a look at the cap table but more often just the summary or even current %age.
Part of the reason people don't do this by default is that it's dynamic. I can promise you 100k shares today and that's what happens 3 mo from now when you start, but hiring anyone else (or you for that matter) will change the %age number.
By the way, especially early on a primary reason you should ask isn't to value the equity but to get a better idea of how the offer values you....
I'm currently on the job search. One of my offers was quite forthright and included the total number of outstanding shares and the fraction I would receive. But this seems very unusual.
The others all treated this information as proprietary/confidential. They either provide an opaque "valuation" of the equity, or give the current strike price ("fair market value" according to 409a) and preferred price (implied valuation after most recent funding round), and strongly imply that the spread here implies that the options are already significantly in-the-money.
Sometimes they just give the number of of options and their strike price.