People generally use 3rd party Nameservers when their Registrar is unreliable or "old school". Most dot-com era web companies used Network Solutions back in th

People generally use 3rd party Nameservers when their Registrar is unreliable or "old school". Most dot-com era web companies used Network Solutions back in the day - and many still use them. However, DNS updates sometimes take hours, their interface is cumbersome, etc. It's become quite common to use someone like Cloudflare for Nameserver/DNS duties (among other things) and keep your registrar where you like.