LED lights are hot to the touch. why is it like this?

This is only because the LED chips or light engines generate heat. This needs to dissipate as quickly as possible. This is usually done with a heatsink, usually with fins. Cold LEDs are more efficient than hot LEDs. They also live longer. Of course, high-power LEDs typically run hotter than low-power LEDs because of the extra heat to remove. Therefore, considering the heat dissipation of lamps, we will use materials with high heat dissipation when designing and developing LED lamps, which greatly improves the heat dissipation of lamps.