Learnt many of the common computer science algorithms back in my uni days but in 18 years I’ve never needed to implement one from scratch except as an interview exercise. I’d say that in 2022 the vast majority of developers don’t need to know how to implement algorithms but we should have a reasonable idea of what the common ones are and when to use them. This applies even for backend developers. If you’re writing your own binary search tree… maybe don’t. The only people who need to go to this depth are people working on compilers, core libraries, and other low level, highly technical use cases.
As an analogy you don’t need to know how to build and service a car to drive one, you just need to know how to drive.