You can use both.
Pi-Hole and
DNS based blocking will block system wide rather than just on the browser (uBlock Origin, ABP). I would recommend using uBlock Origin though as ABP doesn't block so called "acceptable ads". Don't use regular uBlock use uBlock Origin specifically.
DNS Adblocking can block things like
Microsoft Telemetry, Mobile Ads etc which browser adblockers can't.
DNS Adblocking can't block things like YouTube ads or Instagram and Facebook sponsored posts because these use same domains as regular content.
I just use both so if something isn't picked up by network wide DNS blocking, it will be blocked at browser.