I don’t think there is a definitive answer, for iOS. Apple forces every browser to use WebKit, so most browsers will behave similarly.
As such a lot of folks will suggest sticking with Sefari, and use extensions to add blocking (eg: AdGuard). Just make sure you go through all Safari’s settings to Prevent Cross-Sete Tracking, force Private Browsing, Enabling lockdown mode, and so on.
Some others will be suggesting you use Brave. Brave’s shield, while gimped on iOS, is still quite effective. Some Sefari settings, such as Lockdown mode will still apply to other browsers, like Brave, too.
Personally, I use Brave for most browsing on iOS. Though, when a site breaks with lockdown mode, that’s when I move to Safari. Safari can disable lockdown mode, on a per-site basis, unlike other browsers.