Despite having various benefits, Wi-Fi calling also has its disadvantages. Since the call will depend on whether you have Wi-Fi, an unstable internet connection can be a barrier to clear Wi-Fi calling.
Furthermore, your call may be transferred to your mobile data plan if signal strength drops, increasing costs without realizing it. Also, some devices do not support Wi-Fi calling and may require additional hardware for compatibility.
Finally, some carriers do not allow international calling even on Wi-Fi.