[T.B. Yoits]

Major carriers still offer basic flip phones.They often have better coverage than "smart" phones, and work perfectly for voice and text.

Verizon, for example:
https://www.verizon.com/basic-phones/

Verizon doesn't necessarily offer low monthly rates though.

Another option is to buy a flip phone (Amazon carries them) that works on T-Mobile / Mint Mobile and get a basic plan from Mint Mobile for $15 or so per month (if you pay the year in advance).

[TexasGator]

“Major carriers still offer basic flip phones.They often have better coverage than “smart” phones,”

SMART phones may have access to more frequencies than basic phones.