Why is it that Cellphone companies do not send back a notification that a text was not able to be delivered ?

I don’t know about you but it annoys the hell out of me that for some reason I do not get a notification if a text/SMS message I sent is not delivered to it’s intended recipient .
I understand still getting charged for them but would it kill them to extend the courtesy of a “Mailer Demon” message ?
*Some days ago,I kept sending texts to close friend,I thought she was ignoring me and got severely pi**ed at her when it turns out that due to a technical problem her number had to be switched earlier that day,,I found out when I tried calling her & got the “this number is no longer in service” message