How to get all possible paths in 0/1 matrix better way?

You can use NearestNeighborGraph with pos directly:

nng = NearestNeighborGraph[pos, VertexCoordinates -> RotationTransform[-Pi/2][pos], 
  VertexLabels->"Name"]

Row[HighlightGraph[nng, Subgraph[nng, #], ImageSize -> 300] & /@ 
  FindPath[nng, {1, 4}, {8, 9}, ∞, All], Spacer[5]]

If a binary matrix m is given as input, you can use pos = SparseArray[m]["NonzeroPositions"] before the first line of code above.

To show ArrayPlot and the graph together we need to translate the vertex coordinates to align with cells in ArrayPlot:

Show[ArrayPlot[SparseArray[pos -> 1], ColorRules -> {1->Opacity[.5, Yellow]}, Mesh -> All],
  NearestNeighborGraph[pos, 
  VertexCoordinates -> TranslationTransform[{-.5, 9.50}]@RotationTransform[-Pi/2][pos], 
  VertexLabels -> "Name"]]

Use IndexGraph @ NearestNeighborGraph[...] above to replace each vertex with its index:

Maybe this helps. It requires Szabolcs' package "IGraphM`". It is very easy to install and it provides many useful tools for working with graphs.

Needs["IGraphM`"]

A = Reverse@(1 - m);
R = ArrayMesh[Normal@A];
{i, j} = Transpose@UpperTriangularize[IGMeshCellAdjacencyMatrix[R, 2, 2], 1][ "NonzeroPositions"];

vertices = A["NonzeroPositions"][[All, {2, 1}]];
edges = Transpose[{vertices[[i]], vertices[[j]]}];


G = Graph[vertices, UndirectedEdge @@@ edges,
 VertexCoordinates -> vertices,
 VertexLabels -> "Name"
 ]

An now, we can request all paths:

paths = FindPath[G, {4, 9}, {9, 2}, Infinity, All];
GraphicsRow[
 HighlightGraph[G, Subgraph[G, #]] & /@ paths, 
 ImageSize -> Full
 ]

I'd do it like this with IGraph/M:

mesh = ArrayMesh@Normal[1 - m]

g = IGMeshCellAdjacencyGraph[mesh, 2, VertexCoordinates -> Automatic, 
  VertexLabels -> Automatic]

There are two paths:

paths = FindPath[g, {2, 1}, {2, 36}, Infinity, All]

Length[paths]
(* 2 *)

If PathGraph didn't dislike certain vertex names that are lists, we could show them like this:

HighlightGraph[g, PathGraph[#]] & /@ paths

To work around this limitation, we define our own pathGraph function:

pathGraph[path_] := Graph[UndirectedEdge @@@ Partition[path, 2, 1]]