If I understand correctly, the Top 1 and 2, 3, 4, 5 etc. issue is how to make that plasma do actual work. So far the designs which boast Q>1 or are close enough, all produce plasma in short burst and no one has invented a way to make that burst generate electricity somehow. And tokamak design has clearer path to generating electricity but have problems in reaching stable Q>1 at all. This is all very amateurish understanding, please correct me if I'm wrong.

1. We don't have a perfect understanding of plasma dynamics and how they'll react to different conditions. Predicting plasma instabilities before they mess with your reactor remains a big challenge for our computation capabilities.

2. Yeah, material science is also a big one. When you are working with the magnetic forces typical in a modern fusion reactor, your materials undergo a lot of mechanical stress. The "first wall" that has to bear the brunt of the nuclear reactions becomes radioactive. Some plasma ions invariably go off trajectory and we have a "diverter" to prevent them from hurting the reactor but that reduces the temperature.

3. Our reactors aren't efficient enough. Everyone taking about "q" value means the energy they put into creating the reaction to get the plasma to fuse. It's called q-plasma which is a misleading metric. The true breakthrough will be sustained q-total, which will be the ratio of the total energy you get out over the total energy you put in. Nobody in the industry likes to talk about it, because we are decades away from reaching this.

4. Modern designs are becoming extremely expensive. The most serious design right now is being funded not by a state of a country but by the biggest countries in the planet.

5. Someone help me here I've ran out of points

I'm afraid the top 1 issue forever is that it really only works if you are a sun. No need to try and harvest or contain the energy, high energy neutrons damaging the whole thing is a non-issue, and the gravity does the rest.

We already have a fusion source and a way to harvest it from afar in solar panels.

What's pointless for anyone who cares about fusion is commenting on it from the peanut gallery (i.e., any form of social media) rather than participating in R&D in any way whatsoever. The same goes for online outrage: https://par.nsf.gov/servlets/purl/10095997

This entire site is nothing more than a sales and marketing tool and otherwise exists to waste peoples' time.

What's funny is that AI has been failing to be achieved for much longer than fusion energy yet so many here are convinced we're on the cusp of an AI apocalypse.

The thing is, after repeatedly getting excited about commercial fusion power for the past sixty years, it's tough to maintain enthusiasm.

For me I worry it's like the search for the northwest passage. (https://en.wikipedia.org/wiki/Northwest_Passage). Explorers spent about 400 years searching for something that they knew just had to be there, but when they finally did it (1957), it really wasn't important anymore.