Why greenhouse's inside temperature never been infinitely hot?

From what i understand recently, greenhouse gases traps the sun heat (infrared radiation) on earth, by making it harder to dissipate back into space, reflecting most of them again. The exact same process happen in hydroponic greenhouse

If that's the case - why then, hydroponic greenhouse inner temperature don't keep increasing infinitely?

I mean, if we assume the greenhouse is perfectly insulated transparent container (either by several layer glazing or gas-filled), where sun heat strike daily, and less of that amount dissipate back,

Shouldn't it be increasing infinitely? (income > outcome)

Because in mine, the temperature tend to be stable. It did always warmer than outer air in certain degree though

Now i assume other than inside reflection, there might also be outer reflection. So not only it retaining existing heat to go out, its also blocking the new one. That's why insulated glass commercially marketed to keep the room inside cool

But if that was the case, then why we should be worry with this greenhouse effect afterall? The nature seems always be in equilibrium state no matter what;

lots of greenhouse gases = less incoming heat but retain the outcome, little amount of them = more outcoming heat but always up for more incoming one

Or do i missed something?

The emissitivity of anything is σ$$T^4$$. At some point the greenhouse emits energy into equilibrium. The heat inside the greenhouse will eventually conduct to the "glass" of the greenhouse to be emitted. The Stefan-Boltzmann Law is a mere approximation here, but a powerful one nonetheless.