They could have made him a star, yeah. That being said, in regards to making money, what WWE is doing makes sense, to the point where what happens on TV barely matters anymore. It's not Reigns or Strowman making money. It's WWE as a whole.
Not counting Takeovers, 6.
Backlash 2006
ROH Supercard of Honor VIII
Wrestlemania XXX
Wrestlemania XXXII
Wrestlemania XXXIII
Wrestlemania XXXIV
The morning of Wrestlemania XXIX I decided to go to Wrestlemania XXX and spent a year saving for it. Then I thought "why not do it every year?"