there are a couple reasons to read those books, but the most important reason is simply to expand your wealth of knowledge. will you be writing scheme? probably not. will you benefit from knowing all the algorithms and practices that were used back when scheme was more common? almost definitely. because even if you don't use those algorithms and practices, they will surely inform your opinion of which algorithms and practices you do want to use.
i say this as someone who has not read either of those books and doesn't even know what the acronyms refer to: knowledge is good. it'll take you many years to re-learn the knowledge that is already written in those books if you don't read them.
there is a practical limit to how much knowledge you can just throw into your brain, but these surely must be some important and well-renowned books if you throw out the acronyms without clarification, so i doubt the ROI could possibly be negative
i say this as someone who has not read either of those books and doesn't even know what the acronyms refer to: knowledge is good. it'll take you many years to re-learn the knowledge that is already written in those books if you don't read them.
there is a practical limit to how much knowledge you can just throw into your brain, but these surely must be some important and well-renowned books if you throw out the acronyms without clarification, so i doubt the ROI could possibly be negative