The rate limits are because serving such a service at scale without the user noticing requires continuous innovation to get through scale bottlenecks; but with the engineering team greatly reduced, a lot of that work isn’t happening anymore. Typically, you’d get through those bottlenecks by coming up with some heuristics that make it seem like the service is doing a ton, when really it only needs to do little (like by sharding data, or by pre-caching a bunch of stuff). Without anybody to work on those heuristics to fake things, you gotta restrict with real restrictions.
Source: that’s what I do for a living. I’ve been working on some of the highest-scale services out there for over a decade.