Ads are not only present in the browser. For example, there are Smart (not really lol) TVs that have ads embedded right into the operating system (https://reddit.com/r/assholedesign/comments/co5aw4/unremovable_ads_on_my_2500_samsung_smart_tv/). You can’t install an adblocker there, but a DNS based filter will know how to deal with this. There are other alternatives, some are cloud hosted like NextDNS or ControlD, there are other local alternatives like AdguardHome or PfBlockerNG if you run a PfSense Firewall. There are also simple solutions like AdGuard’s Public DNS or Mullvad’s Adblocking DNS servers. If you use an iPhone or iPad, you can easily download a configuration profile that includes the DNS settings for these services. I think NextDNS offers a similar service. On Android, you can just set up Dns over TLS, I think it’s called Private DNS in the settings. DNS adfiltering can’t get rid of all ads though, e.g. YouTube’s mechanism for displaying ads is resistant to DNS filtering. That’s what uBlock Origin if for though.