I went to school in Oxfordshire in the '80s. Some visiting profs from JET joked that fusion was 25 years away then.

Back then things were centered around "can we even do this?" and now it's more of "how do we keep this running more than 5 minutes?".

My impression back then from those profs was that it (fusion) would be inevitable but you do have to think long term, really long term. I'm old enough now (55) to understand that mentality.

I'd put money on something useful fusion related happening within the next 10 years or perhaps 20. I'm not up on the current state of experiments etc but it will happen.

AGI? - lol!

AFAIK superconductors are a major limiting tech. But we are slowly getting better ones, both by discovering more and by learning to mass produce superconducting wire.

With superconductors you can make magnetic bottles.

There’s also some interesting inertial confinement work happening. There the limiter is both confinement and the efficiency of the driver. Look up MagLIF for a hybrid magnetic inertial approach under study.

... and room temperature superconductors! If only we could sort out the feasibility, interdependencies, and priorities, but we just don't know, or well, I just don't know haha.