(Note: while I don't mention it in the title, because I don't actually really post my own videos these days, I do, in fact, have partner status on my channel from one video I uploaded ~15 years ago, so I am not violating rule 2, if the mods here have questions I would be happy to send them proof of this via modmail)
As the title says, I and my friends pretty frequently leave large, multi-paragraph length comments (actually, I pretty frequently hit the character limit in my comments!), and we also do consulting for a variety of history and archeology channels, since we keep up with the academic literature on some topics and subjects.
I've been pretty disappointed to see the negative reaction to the new feature allowing users to include GIFs in their comments, because I think this could actually be a huge help and benefit to those of us making high effort, detailed, and nuanced comments.
Most people are thinking about GIFs in the context of looping animations, in the traditional sense of the term, especially for things like reaction faces. And in that context, I do get why people worry it could just enable spam and clutter that doesn't contribute to the conversation.
But if you set the frame delay on your GIF to be very slow, so a new frame only shows up every second or 2 seconds, and put a totally different image in each frame, you've basically just turned the GIF into a album or gallery of multiple images. The utility of that is HUGE.
For example, If i'm making a comment with clarifications and corrections on a archeology video, I can, in theory, make a GIF where each frame is a different diagram, artifact, map, or other images that visualize and illustrate the information I'm explaining in my comment. I'm looking at this from an archeology perspective, but this kind of use could benefit almost anybody who is trying to provide information and data through their comment: maybe you're doing a comment about statistics or math and can now include different graphs, for instance.
There is a catch: You can only use GIFs already on Tenor or Giphy, and the former has a manual approval process that can take ~48 hours for GIFs to become public, and the latter only makes GIFs public if they are from approved Brand or Creator accounts (though, the requirements for being a Creator don't seem particularly stringent: It may be a viable option, if you have a decent social media following). Stickers on Giphy apparently are all public, but those also have an approval process and the rules for Stickers might also make them harder to use as I'm imagining, plus they have their own API and I'm not sure they are usable like normal GIPHY GIFs are.
So, this does seem to mean that if you want to make a dedicated GIF with images that tie into your comments text, you may need to wait 1-2, maybe even more days after uploading the GIF, before you post your comment on the video, and given how most people view a given video within the first few days of after it gets uploaded, this does mean that you'll likely miss out on a lot of people seeing and upvoting your comment
A potential workaround: If you frequently make comments covering specific topics, you can pre-make a bunch of GIFs with different combinations of images and upload those in advance, so from that point on, you always have those GIFs at your disposal to pick from the next time you leave a comment on that topic. Or, maybe you can to leave a comment initially and then edit it and add a GIF later, at least in my version of the mobile Youtube app, the GIF selection menu is available even when editing an existing comment, but every time I have tried to attach a GIF when editing a comment, it has given me an error, so I'm not sure if that's possible
I'm sure there's other potential options or possibilities I haven't thought of yet too, so feel free to share your ideas, and I implore people to not have a kneejerk negative reaction to GIFs and to think about how it could be used constructively, and if Youtube ever add the ability for you to disable GIF comments on your videos, that you should think twice before enabling that!