Why shouldn't cryptocurrency hash algorythms, resist side channel attack? 2015's Argon2 publication suggests that cryptocurrency hashing like password hashing on backend servers should not be subject to side-channel attack:

Argon2d is optimized for settings where the adversary does not get
regular access to system memory or CPU, i.e. he can not run
side-channel attacks based on the timing information, nor can he
recover the password much faster using garbage collection [17]. These
settings are more typical for backend servers and cryptocurrency
minings.

Why ?
It is generally assumed that cryptocurrency mining is an &quot;offline&quot; process, that is you take one input from outside, and then after a long while you report back with a result. In particular, it is assumed that an adversary does not see when exactly one search starts and when it ends nor do they see how many tries it took you exactly. This makes timing-based side-channels extremely hard - most likely impossible - to execute, even if you leak &quot;a lot&quot; in terms of traditional timing side channels. Furthermore the input to the hash function - which is what you'd want to recover - is only secret right up until you make your outside communication announcing said input - at which point a more sophisticated recovery of it would be pointless...