Consumer-grade 'puters
If you take a look at the time configuration in a typical consumer computer, you'll see one or two NTP servers nominated.
Erm, yes. A typical consumer computer is a consumer of NTP. It doesn't need nor expect atomic-clock accuracy. If it's within UDP-packet timeout time of its ISP's ntp server, that's plenty adequate. Or if it just polls time hourly, daily, or probably even weekly, that'll do.
Need more accuracy? Then you're not a consumer-grade 'puter. You want a competent sysop to configure your NTP with lots of peers, and no doubt other critical setup.
Methinks this is baked in. The protocol is the quintessential UDP user: better to lose a packet than to use a delayed packet! Configuration allows for different levels of operation: peer network, polling frequency, etc. Dammit, when I first set up NTP I used chrony not ntpd, precisely because of its advertised ability to deal with intermittent connections.