Is biotechnology really the future?
No. They have been saying it is the future since 1972. And for a while it seemed it was. But mostly biotechnology is used as a political tool nowadays, with the notable exception of some nations, where there is actually some form of substantial biotechological research outside the government funded research setting. But expect stiff competition, suboptimal working conditions and salary. Unless you are a CEO of course.
what are your opinions? And if so, in which area?
See above, and keep in mind that the definition of biotechnology is ever changing, depending on nation, era and political need.
Such as the engineering area or the healthcare area?
This area is showing a decline in innovation and research is mostly done behind closed doors, which doesn't do transparency much good. I don't think anyone can give you a clear picture on what exactly is going on, except that CROs are controlling the market and the main aim is making a profit. Which in reality means mostly re-evaluating existing drugs (approved and not approved) for new uses, and not new innovative research.
And does biotechnology always lead to engineering?
Depends on the definition. A general definition would be research that leads or aims at a practical application, which per definition would mean some level of engineering.
And what about biomedical science, I would like to do that as a degree, but which does the world need most?
What the world needs most is lawyers and accountants.