No but in the opinion of some of us, giving the number makes for a better-informed decision and a better game.
Also, in the Real World(TM) there are official numbers attached to give Official Meaning to terms equivalent to things like "easy to hit":
View attachment 353176
If the GM isn't using fixed defined chances for his "easy to hit, very easy to hit, moderately hard to hit" etc then he's leaving out information that Official Government Agencies consider Very Important for making informed decisions. And if the GM is using fixed defined chances, then why not just go ahead and use the numbers directly?
(table is from
https://www.dni.gov/files/documents/ICD/ICD-203_TA_Analytic_Standards_21_Dec_2022.pdf)