> whose details didn't matter to the diagram in question.Exactly. Hence why services like AWS were said to be cloud services. The details not mattering was the value proposition being sold.
> PaaS, which didn't exist in the 90s.
It did, except we called it time-sharing back then.
> The cloud could be a symbol for a telephone network, a packet-switched network (including the internet), a company WAN, etc.
While you are right that the parent did specifically say internet, I am not sure there is a meaningful distinction anymore. Telephony, packet-switched networks, WANs, etc. are all, for the most part, a part of the internet now. The exceptions are exceptional and thus can be ignored.