Even if you get as hot as the core, you’re not doing the same amount of fission unless you have similar pressure at the same time, and no you don’t. It’s a bit complicated by the fact the sun is mostly protium, and has low volumetric energy output as a result, but that’s the gist.
Its actually pretty “easy” to get hotter than the sun
An electrical arc is as hot as the surface of the sun.
Even if you get as hot as the core, you’re not doing the same amount of fission unless you have similar pressure at the same time, and no you don’t. It’s a bit complicated by the fact the sun is mostly protium, and has low volumetric energy output as a result, but that’s the gist.