The similarity between mobile internet (CSD) and dial-up wasn't really obvious from the users' perspective because they weren't explicitly making a call to access the internet. The session was established transparently when data had to be transferred, and the time this took was charged as minutes.
Operators always dreamed of a world built on circuit-switched networks that they fully control instead of packet-switched IP networks where anyone can take part and operators are just a carrier. So the big operators started the mobile internet era with the telephony model.
Circuit switching has latency and QoS advantages, but it's definitely not worth the cost for most use cases.
Interestingly, TDM carriers have a latency of approximately one bit per hop and jitter less than that, while any kind of packetized voice such as VoIP has a latency of at least one packet worth of audio, plus one to several packet transmission times per hop, and jitter of several packet transmission times, and packet drop on top of all that. We've actually made quality worse in the name of fitting more services down the same wire, which isn't necessarily bad but it's something to think about.
Operators always dreamed of a world built on circuit-switched networks that they fully control instead of packet-switched IP networks where anyone can take part and operators are just a carrier. So the big operators started the mobile internet era with the telephony model.