The main issue I see with fusion is a chart I saw (that I'm not sure how accurate it was though), that showed the amount of funding needed to achieve breakthroughs over time.

All funding for fusion was far below the level needed for breakthroughs to be made, so until the motivation and funding are at the level needed, I think we will probably not get fusion as soon as we need it. Eg 20 years from now instead of 10