So it indeed depends on your point of view and your projects. Nobody forces you to do something you dont want to do.

Yeah indeed

It depends like Frank_G said on your project, how you work, if you have a team or not, if you begin 3D or not etc ...

if you begin 3D A7 can be a very good engine indeed.
Once you ar no more beginner, you can also try out other 3D tools ! A7 will always have a place for new comers to 3D and kids indeed, and also advanced users that like it (i have A7 , and i think i'll buy A8 ) !!

It only depends on your goal, what workflow you expect , features you need etc ...