90℅ of my calls and texts are on WiFi, either at work or home. But I do also get important calls when out and about, like on a road trip, between stores, etc. For purely outgoing calls and texts, sure, but WiFi only is really limiting.

I have a minimal plan with 1GB data and a few hundred min for $8/month or so, and I tend to use most of that. I intentionally limit it though so I don't get used to always being on data.

But if your main concern is tracking your phone company tracking who you call, that'll happen regardless of it behind on WiFi or on the towers. If you don't use a phone number, that's what end-to-end encryption is for. If you're worked about location tracking, public WiFi has plenty of info, even if you disable location services. I don't think cell towers add all that much risk.