Who I have the same questioned this topic

This seems to be a recurring theme on Verizon. I have poor cellular service inside my home (1-2 bars, sometimes 0). There is unfortunately a hill between us and the nearest cell tower. There is a clear path to a cell tower a couple of miles further away, so I guess the phone switches between the two arbitrarily, but neither signal is good.

Without Wifi calling, calls get dropped constantly (and are poor quality). Wifi calling made things better, most calls are fine, but about 50% of calls get dropped after 15-30 mins. VoLTE on, LTE on, Wifi Calling on. And I have tried all other combinations, including setting the phone to Airplane mode to disable LTE completely (calls STILL drop, but less).

This is especially frustrating when calling places that put you on hold for a half hour and you have to call back, only to have to explain everything again and then get dropped ...

I've been dealing with this for years now. Even opened a case with Verizon. Their final response was "did you try to turn on WiFi calling, as the signal in your area is poor".. Sigh... 

There is obviously a problem with WiFi calling that Verizon doesn't seem to want to acknowledge or do something about. Whether it's the phone jumping from Wifi to Cellular (and dropping it then when the connection isn't strong enough), or the requirements for the wifi connection being too stringent (i.e. a single dropped packet causes the call to drop), not sure ...

I finally gave in and bought a cell booster off Amazon and installed it a few days ago. That seems to have worked. Turned off Wifi calling and now have 3-4 bars in my office area where I make most calls. So far, no dropped calls, even after being on hold for 2 hours (that never worked before). So for others in this scenario -- this may be the real solution, since Verizon isn't capable or willing to fix the Wi-Fi calling bugs. 

Note that I have no problem being on Zoom or Google Hangout meetings for hours without a single hiccup. So I don't think my internet connection is the issue here (I have a very reliable 1GBit/50Mbit connection, industrial router and industrial Wifi 802.11ac access points throughout the house).