The LDC arrangement is broken, primarily because of inflexibility in who is allowed to participate. Previously, those that were available nights or weekends could assist and they did not have to be "exemplary", just in good standing. Now to work on LDC projects (especially in any kind of oversight) you must be available form 7 to 5 Tuesday through Saturday. This means that only those who don't work secularly during the day can participate. Additionally, only construction tradesmen who work in the field secularly are used. You can see how as I go through the requirements, more and more people fall out of eligibility. The net effect is that there are relatively few who qualify and are available. This is a huge rate-limiter for all projects.
Additionally, I still believe that the Governing Body either does not have the funds or does not want to use the funds to build new Kingdom Halls. This is why new builds are rare and most projects are remodels. This is a also a major rate-limiter for the LDC to operate properly.