But even the largest grid infra companies here rely on the telcos for their private comms, for instance:
https://nieuws.eneco.nl/stedin-en-liander-bundelen-krachten-...
Note the mention of "KPN" for this private mobile network that is nominally owned by the energy company grid operators but in fact is operated by KPN (the largest Dutch Telco) and uses their infra.
Which country are you in?