If someone doesn't need to do binary math or write complex sorting algos from scratch you don't test those, just like how you wouldn't ask an athlete the mundane questions I posted above. You might ask high level questions to demonstrate knowledge of sorting, but not ask someone to implement that algo from scratch.
If someone is trying out for the NFL they're not going to have to demonstrate baseball skills, how their shoes are made, engineering questions about how the stadium is built, what software should be used for the ticketing system, or any other questions unrelated to the position. You have them to demonstrate skills directly related to the talents they need to fill their role, like standard field drills.
The same applies to most other low level problems. They should understand the problem and the best practice to solve it. In most cases writing low level solutions from scratch is not the best practice.
FB is a mature company now with a slowed growth rate. They've been dealing with scale and performance for long enough now that it shouldn't be necessary to write all of these things from scratch.
I can assure you that the growth rate has not slowed. Do not use the USA as a proxy for global behaviors.
40-yard dash, Bench press (225 lb repetitions), Vertical jump, Broad jump, 20-yard shuttle, 3 cone drill, 60-yard shuttle, Position-specific drills, Interviews – each team is allowed 60 interviews in 15-minute intervals, Physical measurements, Injury evaluation, Drug screen, The Cybex test, The Wonderlic test
I would consider this set of proxy tests to be roughly analogous to the FAANG interview loop for screening world-class engineers. They're representative tests with predictive validity for the separate, more meaningful task of Game Day athletic performance -- since you obviously can't hold a real Super Bowl as a scouting combine.