DNS adblocking is satisfactory for me; it just gives you empty spaces of removed elements (no cosmetic fix), YT ads, cookie notices, and few paywalls; I can live with.The downside is that they only work within the browser they're installed on as well as requiring some processing power and impacting battery life on mobile as you stated.
The best solution is to use both methods in combination. Using a DNS blocker like Pi-hole, AdGuard DNS, or NextDNS provides a broad, system-wide defense for all devices and applications, while a browser extension like uBlock Origin handles the more nuanced, in-browser cosmetic filtering and specific ad types that DNS can't catch.


