Yeah, if you're just looking for ad blocking, you're right, pi.hole is the better bet.

Little Snitch is intended for per-process, per-connection blocking - for example, you may need, eg, an Instagram uploader app to contact Meta's servers, but an unrelated app should not be able to (and even in the case of the hypothetical IG uploader, you can get very fine grained about the controls - media.facebook.net, not telemetry.facebook.net). In that way, LS does have some advantages over pi.hole in that space - You'd need to set up every single item that you normally get for free from a blocklist, but it gives you much finer control over what's getting blocked and much better visibility into what connections your processes are trying to make.

Again, I don't think Little Snitch is the right answer if you're looking for ad blocking specifically, and if that's the extent of your privacy concerns, pi.hole's a better bet. Little Snitch is a per-application connection monitor and firewall - it _can_ block ads, but that's not its primary purpose.