But there seems to be a dearth of equivalents at a larger scale, for larger scale construction projects. And yet to produce them would be relatively easy. There is already lumber in standard sizes, the ubiquitous 2x4, amongst others. What is needed is connectors for these, for a range of joints: corners, Ts, etc.
It may be possible to have a two-step connector system. One piece of plastic is screwed permanently (or at least semi-permanently) into the ends of the piece of wood. And another piece of plastic joins those plastic fittings, with a simple clip-in and clip-out. This way, each length of wood can be quickly reused in many different configurations, as can the plastic fittings that aren't permanently fixed to the wood.
Obviously the fittings could be made out of metal rather than plastic if load is anticipated to be significant.