Vulnerabilities in LTE/5G core infrastructure, some remotely exploitable, could lead to persistent denial-of-service to entire cities.

The 119 vulnerabilities, assigned 97 unique CVE identifiers, span seven LTE implementations – Open5GS, Magma, ...

It's an extreme example for sure, but it really all comes down to older phones not having the right antennas, radio hardware, ...

Cellular One and other mobile carriers are phasing out 3G networks to prioritize advanced technologies like 4G LTE and 5G.