Making a sustainable fusion reaction is hard though. Mostly because you need to start a chain reaction of sorts, and it runs hot as all fuck. The H bombs used a regular Plutonium A-bomb to get the energy needed to start the fusion reaction and you can see from the videos of that they basically make a mini sun that vaporizes everything nearby.

You can't stick that in a bottle. The amount of energy you need to ram atoms together is huge. Once you do it at any sort of scale the amount of energy you get out is basically impossible to control.

They're trying to find ways to do it at lower temperatures that can be contained, cold fusion, but that's easier said than done. I think eventually someone will figure out an efficient way to do it. But the whole process is gonna be pretty complicated to get anything useful from it.

Stars manage it because of gravity. The sun stays together only because it's gravity is so massive that it can hold the explosion in a kind of homeostasis which keeps the core hot and keeps the reaction going. When stars run out of fuel they shrink which makes the core hotter and fuses heavier and heavier shit until eventually the whole thing converts most of it's mass into iron which it can't maintain an exothermic reaction with and the star implodes and either breaks physics by imploding faster than light creating a black hole which is essentially a star "frozen" in place because the universe can't hack it, or it doesn't and you get an explosion that can be see from even distant galaxies due to how fucking huge it is.

So trying to recreate that on human scales just is quite difficult. It's not easy.

Fission is pretty simple in comparison and we already basically have nearly free unlimited energy if we build those, they're just expensive to start up and maintain but they'll pay for themselves in the long run. Hell children have managed to build fission reactors in their garages much to the changrin of the government. It's a much simpler process. Since of course, breaking apart shit that already was fused is easier than fusing shit.

The amount of energy we need to spend to not only fuse the hydrogen but to maintain a Controllable reaction is so great it's extremely difficult to make that process cost effective. Like it's easy to fuse the shit, but the first human made fusion reactions literally needed to be triggered with nukes. You can't go setting off nukes in a power plant.