NextDNS and similar services basically host the pi-hole on your behalf. Pi-hole setup involves installing packages on a device that will handle your ad content filtering and related network configuration; NextDNS involves getting a URL to copy-paste into your phone, computer, or network’s DNS configuration settings. The latter is far less labor-intensive. The trade-off is that you have less control over how things get blocked. Pi-hole is more of a local solution than NextDNS, but if you don’t want to fuss with the tech and just want to start blocking more ads, go with NextDNS (or similar).