Funny you should write this, as I just logged on to a massive art dump myself. Though about half of them are stream announcements.

Chances are pretty good we both logged in to the same art dump. I usually go through and delete the stream notices first. Otherwise my submission backlog would probably be twice or three times its size. I also delete the majority of the YCH auctions and Patreon notices. Other than that, I try to look at almost everything else that remains. I usually make most of my progress on the backlog over the weekend but I didn't this weekend and most of what progress I was able to accomplish got wiped pretty much by one artist.

I'd imagine that some artists may be in a similar situation as yourself; limited windows of time to actually prep and post, so they update in chunks.
Your frustrations are valid (I'm ever-working on a very large backlog D: ) but some artists may be dumping art in bulk if RL limits when and how they can.

(Or maybe there's some secret to larger art-dumps we're missing out on!)

Not sure I can excuse how file-size is creeping higher and higher; I think 'how big is this file' rarely comes into the equation even though good compression can still fit :d

Actually there isn't much restricting me from updating. I'm usually online daily. What does limit me most is a lack of uploadable content. What you do usually get to see from me happens because I get to a point where I'm getting tired with an image to where it becomes a chore to work on but it's in an acceptable enough state for scanning. Lately it's taken me longer to get sketches to that stage so that doesn't happen as often as the daily uploading of a sketch or two I was doing a few years ago.

Even when I did have the content, I tried to limit my uploading to just a few images a day to spread them out over a period of time, usually having something relating the images going up to one another. While I don't know how other artists live, I'm guessing the majority of them have a good, fast, reliable internet connection and access to it on a daily basis and the capability of uploading at least one image almost every day. Sure, it might me watching one less cat video that day but it would also mean I wouldn't get buried in sometimes 50 or 60 submissions at a whack on top of the about that much I usually get from the several artists that post one or two works most days.

When I do have content to scan, I usually scan it at a higher resolution, then reset it to a lower one for viewing, resize the image so it's acceptable for FA's size parameters, then compress it about 20% so I'm not waiting forever for the image to upload and by extension so my viewers won't wait a long time for it to download. I don't have the best computer set up but I do have a decent sized widescreen monitor and with some file sizes and images, I might be capable of looking at an elbow or one gigantic eye at full resolution. To see more of the image, I'd either have to be using a television on the higher end of TV sizes these days, the Times Square jumbotron, or being willing to make a printout the size of a billboard. What's the use of a file size that big on the internet?

To me all of this comes down to consideration or a lack of it for one's viewers. I've gotten pretty close to unwatching people that chronically flood but I have this almost ridiculous compulsion to see what work they'll do next especially for those I've been watching for several years. I know they probably won't change their habits or even read what I've written but I've said my piece and voiced my frustrations, which I have the right to do where I live - so far. Now I'll go back to my task of dealing with the backlog as best I can, though I can sure sympathize with Sisyphus on how pointless and never ending it seems to be.

Off the cuff, I wouldn't think speed of internet is the large difference between how artists choose to update their galleries, but rather a blend of the following;
• Where they're accessing the internet
-- If they live at home or a shared living space (college dorm?) then there may be limited windows of time to upload furry art without prying eyes.
• How many gallery sites they manage
-- A lot of gallery sites are floating around these days, including services like tumblr and twitter. An artist may do them in large batches because starting and stopping such a 'machine' is work in itself, and starting/stopping that 'machine' in 1 large session is easier than 4-7 sessions throughout the week. (e.g., sitting down to copy/paste descriptions and uploads between FA, SF, IB, DA, FN... and Hentai Foundry and Tumblr and Pixiv and is Y-Gallery still a thing?)
• If they do small/fast Commissions via Streaming.
-- Possibly a Chicken or Egg, but if an artist's main source of art commissions is streaming, then they may make a bulk session of it when they sit down to work (journal that they're doing a stream, announce\open the stream, take commissions, post the commissions, close up for the day)

Of course this is very off the cuff and artists come from all walks of life, likely no single answer.

Fortunately noone I watch does that.

When I see art dumps I usually look for your stuff among it, as a shiny gem among common stones.