All programming philosophies are about state

Functional and declarative are the same to me

Forth in its simpler implementations seems like it goes about as far as one could conceivably go in terms of maximizing state, or minimizing non-state. No parameters or perhaps even local variables, everything is just pushed onto a stack (or one of many stacks) that can be freely manipulated at any point. No major opaque control flow mechanisms, ifs and loops are implemented as functions operating on an exposed "return stack" which can be freely manipulated. No opaque function definitions compiled into a binary, function implementations are placed in a data structure that can be freely accessed at any time. No separate compile stage that manipulates state otherwise inaccessible to the program, compilation happens at run-time by manipulating freely accessible data structures, and the "syntax" for compiling things is essentially just function calls that manipulate globally accessible state based on what's in the input stream and you can write your own alternatives if you want.

If the functional paradigm tends towards avoiding state, then it would seem to me that forth does the opposite: making almost everything a part of the state of a program that a developer can access and manipulate, even things that most structured programming languages do not expose to the developer.

They forgot Immutable! The best way to handle state.

State machines?