I think the comment on groups is a good thought! That's also the reason I keep advocating for a more robust tagging system here on Tapas. Giving creators the power to make their own categories would make a system where it's much easier for readers to find "more stuff like this," and easier for creators to find (or create!) the categories relevant to them and add their work to those categories where readers can find it more easily.
There's nothing really stopping tapas folks from making groups, though!! - like, creators could easily get together with other creators to promote each others' work -- I know I got a pretty decent number of eyes when another Tapas creator linked to Runewriters in their comic's header! Lots of comics outside of Tapas have groups where a bunch of creators of a similar genre or quality join forces and have a rotating ad on each others' websites to advertise each other, and occasionally participate in events together, and promote each other -- it seems like it wouldn't be too much harder to set something like that up between Tapas creators.
The thing that makes this stuff tricky, always, is quality control. Deviantart is a good example -- how many people actually set it up so that they see whatever random thing was most recently uploaded on the front page? The quality of work displayed when you set this as your homepage SINKS (which, incidentally, reflects on website as well -- how long would you, as a reader, stick around on a site where the entire front page was amateurish scribbles?)
So realistically, you don't want it to be open season on the front page; most readers don't want to dig through a bunch of comics that nobody liked in order to get to the good stuff that other people enjoyed, just for the sake of being more likely to encounter a diamond in the rough. Sure, you want people who are doing good work to have a chance at being noticed when they're small, but you also don't want to display Literally Every Small Comic or else the overall quality suffers, and then no reader is gonna check out that section. Again: Readers WANT websites to display the good stuff prominently and weed out the bad stuff. Most of them don't WANT to dig through the bad stuff. If you make a section that doesn't weed anybody out, then no reader is going to use that section and therefore it doesn't do creators any good.
You could argue that popularity isn't a perfect measure of goodness, and you'd be right! There's plenty of comics that aren't popular yet, but are good! But then, the only way to pick those out is to have some kind of juried process, and often, the staff of places like Tapas is simply not big enough to have a whole bunch of regularly, thoughtfully handpicked up-and-coming comics. And a process like that is always gonna have its own biases, and its own frustrations, from being a fallibly human endeavour.
So I really think that the most effective answer is for creators to look for ways to set up the kind of services they want or wished for among themselves, rather than trying to get them from the hosting website! (note, too, that when creators band together and make things like this on their own, sometimes Tapas staff will reach out to highlight and promote it -- the Holiday Collabs in the past are a great example!)
Quality control is going to be an issue here, too -- if you just promote literally anyone who asks you to promote them, then sooner or later your recommendation has no worth, and readers won't listen to it. And many folks with comics that they're proud of aren't going to want to display images or links to work that's at a way lower level of polish and care. But comic creators could make apply-to-join groups that promote each other regularly, where any creator could apply to join and the rest of the group could determine if the newcomer's work is up to par, and accept or deny.
There's definitely some interesting thoughts here -- the trick is to figure out the most feasible/effective way to implement those ideas as creators!!