One full time job equivalent can buy a lot of tooling. Tooling that not only replaces this role but also shifts the feedback a lot closer to dev introducing the breaking change.
Every large project has this position. Smaller projects it isn't a full time job and so they distribute it amoung the team members and don't track the cost. Larger projects it is too large for a full time person and so they are forced to distribute the costs of this and just cannot track the costs. We happen to be in the sweet spot where a full time person can do the job and so we can track that cost. However make no mistake everything this person is doing is done on every project.
I agree with tooling being important. the person we have doing this job is a great engineer who automates everything he can, but there is still a lot of work that needs to be done. Some of it cannot be automated. (many of the problems are people problems)