Yes, because in a large organisation where your internal services are just "out there" for other teams to use, and you might not personally know the people who

Yes, because in a large organisation where your internal services are just "out there" for other teams to use, and you might not personally know the people who are using your service, you basically need to protect yourself/your service as much as you would for any external service. It also helps your service know how much it needs to scale and size itself if a team gets in touch and says "Hey we are making Service X - the default your service offers is 100 QPS but we think we will need 1000 QPS - can you support that?". In a small org where you know/roughly-know who is doing stuff then it is probably less of a concern as you can go walk over to their desk and have a chat about what they are doing or let them know they're sending too much traffic etc. This is harder to do with an org with 10s of thousands of engineers spread across the globe and in different timezones - you might suddenly get huge amounts of traffic at 3am from a team on the other side of the planet who just launched a feature you had zero idea about, and they're hammering you with 100x the QPS you usually get.