You have probably already noticed it but this forum also has its own
Gallery. MelonLand itself is an 'arts' forum so could you clarify if there is anything in particular here that you find lacking or unfitting (if any)? You could always just share your art/writing here and people generally seem responsive after all; or is it that you are looking for a community that is
just for art?
DeviantArt's reputation is kind of bad these days (and their ugly redesign does not help) but
they do have a forum that still has daily posts.
crittertime.fun is a 'general purpose' forum but it specifically has a section for arts.
Some other still active forums I found are
Crimson Daggers and
JWJ (much slower, but has posts from this year).
If you are into virtual pet games, most of them have a forum specifically for artists, although they tend to be focused on graphics/fan art for the game itself instead of 'general' work as a whole.
Brisray's Webring List is a directory for most active webrings these days, several of which are art-focused.
Otherwise, most people seem to congregate on Discord servers these days, but I can understand if you don't like that option.
I hope other people will be able to share more helpful suggestions; unfortunately I find the issue with a lot of small forums or analogous communities is that people (especially those who have gotten accustomed to 'mainstream' social media) tend to just drop a post or 'content' and get bored when nobody engages with it quickly enough, without them themselves bothering to look at or talk to people already there. Not implying you are like this, so much as just observing that this is the case for many forums in general.
I think for that reason a lot of people don't really want to stick around a place full of strangers they are not engaged with, and when it comes to sharing art/writing it's a lot easier to find a small personal 'circle' or a community that is specifically centered around something more specific or niche. 'Art/writing' is a really broad scope and even communities 'dedicated' to it will often be filled with people who don't use the same medium/genre/style/etc. and are thus not all that interested in engaging with each other (or feel unequipped to give any productive feedback/interaction despite theoretical 'interest').
For example, I have a personal forum that is 'about' a webcomic, but discussing the webcomic itself isn't the only thing people do there. The readers of the comic tend to come from the same demographics (people with a particular disorder that the comic is about + fans of a different story the webcomic's inspired by) so even when the people aren't talking about the comic itself, they tend to already have a thing here or there in common, and whenever people share about their original work the others are receptive because they centre on the same themes, ideas, etc. that they were already interested in.
Is there any specific theme/topic/etc. that your own work centres on? Maybe you will find more luck in looking for communities about what your art is
about instead of just about art as a whole. Either way, good luck with the search!