Why a bulk encryption key and frequently used key needs to have a shorter lifetime? In NIST standard (NIST SP800-57), the bulk data encryption key and other key material that is used frequently have a short lifetime. As quoted from (Sec. 5.3.6, point 6.b.):

The originator-usage period recommended for the encryption of large volumes of data over a short period of time (e.g., for link encryption) is on the order of a day or a week. An encryption key used to encrypt smaller volumes of data might have an originator-usage period of up to two years.

Also, more generically, in Sec. 5.3.1. Factors Affecting Crypto periods, it stated in fifth entry:

The volume of data flow or the number of transactions;

I do understand that, intuitively, the more a key is used for an operation, the more &quot;information&quot; about that key in this operation is revealed. But I can't figure out a more concrete rationale behind it. Since such consideration is for rather generic (does not seems to be based on the property of a specific key type). I wonder if there is any generic / theoretical framework describing how using a key reduces the &quot;reliability&quot; of its secrecy?
Most symmetric encryption techniques use an $\text{IV}$. An important characteristic is that the $\{key, IV\}$ pair must never be reused.
The $\text{IV}$ is randomly generated for every use, and some cipher modes (eg: GCM) break it down into one part for the nonce, one part for the counter. eg: for a 128 bit $\text{IV}$, the nonce is 96 bits, the counter is the remaining 32 bits.
The counter usually starts at $0$ for every data and is incremented for each block. So we only care about the nonce.
Given a 96 bit nonce, the birthday paradox tells us that the probability of nonce reuse after $2^{32}$ uses is approximately $2^{-32}$. The $2^{32}$ reuse probability is recommended by NIST.
To reach $2^{32}$ uses in a week, we need to perform approximately $7000$ operations per second. This is not an outrageous number, link-level encryption can easily handle this.
So with heavy usage of a symmetric key, we want to make sure we limit the number of uses to something well below the probability of nonce reuse. Taking safety margins into account for the above example, we might pick one day as a reasonable lifetime.