Classic NTP is hardly the only game in town. For example, see the NTPsec work in progress: https://www.ntpsec.org/ which I'll probably transition to someday, maybe even get an el-cheapo GPS receiver now that I'm not effectively living in a basement.

And I've personally be using chrony for a while, although my needs are significantly less than whatever level of accuracy it provides. There are some other clients out there as well, such as OpenBSD's OpenNTPD, although I have a vague memory of it having issues of precision, congruent with the distribution's focus on security.