Cutting edge chip production is still highly dependant on possessing the required experience within your institution. You may be able to build a FAB from part

Cutting edge chip production is still highly dependant on possessing the required experience within your institution. You may be able to build a FAB from parts, but that doesn't mean you can immediately start mass producing the latest CPU's or memory. And there are other comparably complex project's with similar issues (like designing rocket engines). I think the same applies to reactor building where only a few companies know how to do a particular thing (like build a reactor vessel). Cutting edge development is unavoidably going to be limited to a small group of people who have limited capacity. Merely maintaining that capacity is tricky.