Personally I find AdGuard (not to be confused with AdGuard Home, they are different products) to be the best adblocker out there, both for MacOS and iOS. What's great about it on MacOS is that it's not a browser plugin, it's an application that runs on the Mac itself. This means you can add any app you want to be filtered, not just the browser. I use a messenger app that likes to show ads. I added it to AdGuards filter and now it's clean.

Also with all the changes that are potentially coming to browsers (chromium) not allowing adblocking this is a future proof solution because again, it's running at the OS level and not inside the browser. It doesn't matter if Google tries to stop you from blocking ads because it's all done externally from the browser where they have no control.

You can add a bunch of other features as well like advanced stealth which randomizes your browser fingerprint, helps to avoid deep packet inspection by your ISP, encrypted DNS, encrypted Client Hello (in beta currently).. it's really the whole package. I feel like it's worth paying for because it does much much more than a simple adblock browser extension.

This question keeps popping a lot these days.

I switched from AdGuard to Ghostery.

It's super light, and has built-in Never Consent to CMP in Europe that also have the side effect to prevent advertisers to display ads (because the consent status is unknown, as if the website itself had no CMP manager, which scare the shit out of advertisers)

I also bought Vinegar to kill every single ad on YouTube, simply by replacing YT player with the HTML5 one. And even Google can't do shit against that.

I use Wipr; have for years and have never had any notable issues.

Wipr without a doubt! On all Apple devices. Thanks Kaylee for that wonderful app!

It isn't a bloated software like some other extensions and adheres to the way Apple intended Content Blocking Extensions to work - it is fast and private.

I'm a fan of a multi-tiered approach.

For system wide, I update/replace my etc/hosts file with the one generated here. The advantage is that this blocks ads system wide—not just in Safari. They simply cannot load at all on your computer. It's free, but updates have to be preformed manually.

Next, VPNs often add an additional layer of protection. Apple offers one with iCloud subscriptions, but I'm also fond of Lockdown

And then finally for an actual Safari extension, I use 1Blocker, which I guess actually answers your question.

I'm using Wipr, haven't had any issues with it really. The only downside is it can't block YouTube ads, but I think that's a limitation of all Safari content blockers.

I also use Firefox with uBlock Origin for the sites Safari can't handle.

What is it exactly that you want to customise?

After reading through some posts on the MacRumors Forums, as well as your comments, I'm going to stick with Wipr for the time being. I think I just wasn't using it properly, but now that I've educated myself on it a little bit more (who knew, huh?), it should work fine for my liking. (P.S. I wouldn't normally make a post like this, but in an effort to be more active here on Lemmy, I figured why not?)

I'm a big fan of AdGuard as well, and the ability to customize what I block and what I don't block is why I use it. It's a sort of fire-and-forget application for me though. Once I had the basic lists that I knew to work for me setup and my upstream DNS set to NextDNS (or any adblocking DNS) it covered all of my use-cases. That said, Wipr tries really hard to balance removing ads without breaking stuff, and if it works I'd definitely recommend sticking with it. You can get almost the same effect of "system-wide" adblocking by just using a DNS server that blocks ads.

I don't have a Mac (yet!), but I've been researching apps a lot lately and there's this rather new browser with a built in ad-and-tracker blocker called orion in open beta
Alas it isn't open source, but it is free, based on WebKit, and even supports extensions from both Firefox and Chrome

Adguard is recommended by privacyguides:

https://www.privacyguides.org/en/mobile-browsers/#adguard

I've been using Safari as my main browser on mac for a LONG time then on a whim i decided to check out Brave. It kills ads for me SO much better and even scores incredibly well with EFF's https://coveryourtracks.eff.org/ . I do run uBlock Origin with it and I can go to damn near any site including Youtube with no ads at all. Maybe I'm missing something but so far it's working too well for me to switch to anything else.