This is known as the "phase ordering problem". Despite the super-exponential (even unbounded, because phases can be repeated) space, I think this is more tractable for certain subsets. For example, in sea of nodes compilers, like HotSpot, Graal, and TurboFan, forward dataflow analyses that do reductions (i.e. always make the graph smaller and/or cheaper) can be combined into one mega-pass where they positively interact each other. The problem is that some problems are not forward data flow problems and some transformations are not simple reductions. Also, some phases make use of type information which can be destroyed or obscured by lowering.
