First, AdGuard goes beyond basic ad blocking. It also blocks tracking, malvertising, phishing, and more threats. This provides a major security boost you won't find in most ad blockers.
Second, AdGuard handles ads system-wide, not just in your browser. It blocks ads in apps and games on iOS and Android too. This consistent ad-free experience across devices is invaluable.
Third, AdGuard uses significantly less memory and CPU than other leading ad blockers. The lightweight build optimizes performance, especially on mobile. It's snappy and responsive even when blocking ads everywhere.
I do not think, that AdGuard - $5 lifetime priced is better that free uBlock origin ad blocker.
First, malvertising, phishing is blocked with antivirus. Addon can not do that effectively, because large antivirus companies have millions of users, with good databases. Tracking is blocked with browser, if you have good browser, which also have millions of user, so tracking is developed.
Second, forum users mostly use desktops and laptops, therefore iOS and Android ad blocking for them is not important.
Third, less memory and CPU using nowadays for addon is not important in Windows/Linux.
Plus, UBlock origin is much more popular, because it is free, and have localised lists for each country.
The only real and big advantage with AdGuard is stealth mode for Youtube, if it will work.