Is "The Course" still definitive, or no longer all that relevant?

It's been a while since I bought a poker book. Those dozen or so I own, I've thoroughly read and re-read over the past 20-ish years. But they were all written before the advent of solvers. I think the most recent publish date was 2008.

I haven't read "The Course" yet, and was thinking about picking it up, having seen it recommended widely on this site. If I'm right in guessing that this thread's OP was the author, Ed Miller, I'm inclined to go for it.

But I was just listening to an episode of the Thinking Poker podcast, titled "Everything I Need to Know About Poker, I learned in the Last Two Years" (from November 2023). The point made in the podcast was that over the past few years, solvers have changed so much about how the game is played that everything which came before now seems antiquated.

It got me wondering if "The Course" first published in 2015, is still relevant, and still viewed as being the definitive text on crushing live low stakes, or if it's now viewed as being out-of-date knowledge, no longer applicable to today's game.

Is it still worth the investment, or are there other books that have superseded it? The only thing holding me back is the $50 price tag and the fear that the concepts within are past their sell-by date.