1) The improvements in the output of FDM printers is in good part due to switching to lower-strength materials (e.g., ABS -> PLA). It's great news if you want to make casting molds - but not so great if you want to directly fabricate durable parts.
2) There is no gradual progression from the familiar FDM extruders to SLS, SLA, and similar technologies that produce high-accuracy parts or can work in metals. These technologies are inherently messy and have other surprising trade-offs, and are suited chiefly for very dedicated hobbyists and for quasi-industrial applications.