Mirror Coat is a bit of a niche.
While it’s definitely usable due to Cradily’s solid special bulk and access to Recover, there’s always a significant risk of wasting a turn. However, compared to many of Cradily’s other moves, it’s still one of the better choices. Alternatively you could run Giga Drain (mostly redundant alongside Recover), Wring Out, or Stealth Rock. Since you’re running a stall set, Rock Slide and Wring Out are probably not as good as mirror coat. Stealth Rock, on the other hand, can be very decent.
Even though Mirror Coat is somewhat situational, I’d still recommend keeping it.
If you do want a replacement, Stealth Rock would be the next best option.