The number at the upper-right corner of posts is also a direct link to that post, so you can right click it and choose "Copy Link Location" (or your browser's equivalent) to have a URL copied that you can use. (Make sure you surround URLs with [url]...[/url] tags or use the Create Link toolbar button whenever you're not placing them at the beginnings of new lines; the forum's parsing of plain URLs without any tags is buggy in the version this site's currently using.)
Yeah, modern YAF.NET is a comedown compared to the earlier incarnation and I ranted about it myself at the time. Such is the way it is these days with software and websites in general, where "upgrades" or UI "improvements" often actually mean things getting worse. But the earlier incarnation is of course no longer maintained by the developers, so anyone still using it would be on their own in patching or working around security vulnerabilities and compatibility issues arising thereafter, and Eutychus has enough on his plate to deal with in administering this site and in real life. And there's worse forum software and designs out there. At this point, I'm just grateful that we can still talk cartoons on a traditional independent discussion forum. The very business models of social networking platforms such as Facebook, Twitter, and the like revolve around tracking users' usage habits, manipulating them into as much "engagement" as possible to maximize the data collected, and monetizing that data by selling it to advertisers. (As I've repeatedly seen it put, these companies' actual products are their users.) And most in the classic animation community, as with many tech consumers, are just fine with this abuse just to be in on what's fashionable.
One thing that would help is if people would edit quotes in their replies to only contain the post they're replying to, and/or strip out images or video embeds; huge blocks of nested quotes and needlessly-quoted images don't do readability any favors, on any forum.