my 2 pennies....
rrtcm could be considered awful if you aren't interested in cards, but then again, your audience maybe.
I was a chef for many years and although I despise cauliflower with a passion have been asked for creme de barry (cream of cauliflower soup *shrugs* dont ask me why on earth the French called it barry) more times than it's taste should allow in my opinion, so still made sure I knew exactly how to make it.
A bit of an abstract example, but I think it makes sense
I know rrtcm may not be considered essential to a magician, however even if the magician themselves do not like card magic, they may be presented with someone who asks simply, "know any card tricks? i love card magic".
Then what do you do?
No card gimmicks on you. Only a plain deck in your pocket and you know just one self working trick with cards dealing them into 7 rows until you find their card that most people have been shown every Christmas at the family get together.
I have been doing card magic for friends and family for years now, but until about 4 years ago when i picked up royal road, they were practically ALL self working. I was adived by a cardist to go read it, he had been moonlighting as a waiter where I worked and had just baffled me with what I know was very easy and not exactly a trick that he'd learned, more something he threw together on the fly. Within minutes of mastering the very first chapter (as it suggests in the book, figure out each chapter before proceeding) I think my card trick repertoire increased ten fold even though it only shows you 4 or 5 actual tricks each chapter. It gives you ideas to use these techniques, but the main essense of the book is that instead of just teaching you trick after trick, it shows you from the very beginning ways to achieve certain, how shall i put this without getting an edit, conditions that can really help you in revealing a card. The rest once you have learned a few methods, even in the very beginning of the book, is up to you and how you imagine the spectator could be gobsmacked when you show them a card that they themselves put slap bang in the middle of the pack.
There are some astounding card tricks in there, but it's main aim is to show you chapter by chapter a new method to master that you can use for hundreds of other tricks. The first you could have at least show-to-friendsable by the time the sun goes down the day you get the book.
My absolute favorite is "design for laughter" and you get shown that within 80 or so pages....very easy but completely baffling to most (can be done in their hands for whoever has read it....they have no idea what the .... just happened. it's all in the order you place their cuts

my patter rocks!)
Put it this way, for ten quid or less, you have as many card tricks under your belt as your imagination will allow...... just in case you hear....
"go on, do something with the cards, ALL magicians do cards!"
*groan*
"oh all right then, but I don't know any good one's"
with that, you proceed to pull their chosen, signed card from your flies using very little effort.
I was a chef, I bought this book.
You want to do magic?
draw your own conclusions
