You've asked a fair question. Dealers have specialized tools to ensure fast and reliable repair procedures. Any job can be done different ways but doing it fast and right every time means special tools.
On the pushrod engines there isn't much that needs the SVO tools, and there are work-arounds that are fast and don't damage stuff. Same for the M40 transmissions. If you want to dig into the differential there are special tools for the Spicer like a housing spreader.
Some people do things a dealer shop would never do, like using the "rope trick".