Why is the processor on a big board?

Question

Processors

In general, the processor is a chip that lies on the board, allowing you to insert it into the motherboard. Why do you need such a large adapter.
Example:

Answer 1

To solve problems with heat, dirt and mechanics. The housing dissipates heat and protects against shock, vibration, dirt, etc.
Inside the chip case, perfect cleanliness, by the way.

Answer 2

The processor has a lot of inputs / outputs, well, or just contacts. They now barely fit on the "adapter" - look from the bottom of the processor. If it is reduced, the area of ​​​​the contacts themselves will correspondingly decrease, which is fraught with a ton of problems: from an increased likelihood of mechanical damage to an unreliable connection.

Answer 3

So that the school can measure stone upgrades without the need to solder it.