Not anymore. You can just find one on the app store and install it, almost exactly the same as you do in a browser's extension "store". It won't be as good as uBlock but it certainly works fine even in Safari.
ublock origin lite is straight up on the app store now, should work with any moderately recent version of iOS/iPadOS. Installed this on my family's Apple devices and it works pretty well.
There's also been other adblock apps for a long while, though (adguard comes to mind).