That's a fight we lost two decades ago now unfortunately. Nearly any modern-ish API is a JSON-based RPC. There's nothing wrong with that, JSON RPC is a plenty fine solution for many common use cases, it just isn't REST.

Note that there is also a standard for JSON-based RPC systems, called JSON-RPC [0]. Not every JSON-based self-titled "RESTful" API uses JSON-RPC.

[0]: https://www.jsonrpc.org/