I wonder if the reason roll-to-roll processes haven't caught on is that there is so much capital investment in IC/wafer processes at scale that the unit economi

I wonder if the reason roll-to-roll processes haven't caught on is that there is so much capital investment in IC/wafer processes at scale that the unit economics just don't add up (until/unless very large capital investments are made to scale up and refine margins on roll-printed circuits). If this is the case, are there areas to attack the market? Any smaller markets which don't attract the attention of major electronics fab and might be delved to help bootstrap roll-printing? Any old/displaced technology areas that no longer have the advantage of large fabs/infrastructure investments where roll-to-roll processes could come online to replace them at competitive prices? Any idea what it'd take, in terms of unsolved R&D and in terms of capital investment, to create a roll-to-roll process capability of printing some circuit that would be cost-competitive in some area like solar cells or maybe simple ICs?