That’s exactly how every platform team starts. There is inherent tension between accelerating developers and building their own systems, though.
In my experience, the platform teams developed an idea that their conceptualized system would accelerate everything once it was done, but working with product teams was a distraction from getting it done. They also didn’t like the idea of deploying something now and then having to rework it later when their ideal system was ready. So they defaulted to gate keeping, delaying, and prioritizing internal work over requests from the product teams.
The only way to get things done was to leverage management chains to put pressure on the platform team to prioritize getting your thing deployed. This was constant no matter how much headcount the platform team received because with every new hire they developed new ideas and goals to add to their internal roadmap.
It’s not supposed to work like this, but it plays out this way in many companies.