Without digging into the rationale behind access time tracking, its write-amplification effects in particular for SSDs, or the fact that it can be somewhat mitigated by the relatime and lazytime mount options:
Can we produce a list of the (allegedly very few) applications that actually require atime support, and how (severely) they break if it's not used?
Naturally, a number of applications that inspect atime indirectly rely on it, in the sense that they report a wrong atime if it is not tracked (e.g., listing or forensic tools). This question should only concern applications that actually exploit this piece of information, rather than presenting it, and which break at least to some extent functionality-wise if they are used on data without atime support (e.g., the prime example of mails not shown as read).
