Since I started working for Apache APISIX, I have tried to deepen my understanding of REST via various means. Did you read my review of the "API Design Patterns" book?
In the current literature, REST is generally promoted as the best thing since sliced bread. Yet, it comes with lots of challenges. In 2010(!), Martin Fowler wrote a post on the glory of REST. He lists three steps for an API to become truly REST: