Assuming people adopt MCP then: - JSON over the wire instead of binary - Schema optional with the spec only defining the envelope - Lack of inheritent suppor

Assuming people adopt MCP then: - JSON over the wire instead of binary - Schema optional with the spec only defining the envelope - Lack of inheritent support for code generation - Poor support for flow-control or multiplexing - Deadlines/timeouts, compression, per-call metadata, bi-di streaming, TLS, load-balancing hints: none of it standardized - No inbuilt payment mechanism