HONESTLY...... Im not sure you can know. But it's one of the factors that's in there if you're looking to find out where you stand, I think?
I guess my example is, when I first considered joining Tapas, I looked around to see if there was anything like my comic here, and I ended up finding Sanity Circus. It was in a similar-ish style, a similar slightly-fantasy genre, with some creepy moments and some funny moments and characters who were both weird and thoughtful, and I felt like our work had a similar level of expressiveness and humour and cool moments. Obviously it'd be impossible for me to say for sure, but it was close enough that I was like "okay, I have the potential to do well here." Sanity Circus updated more frequently than I did and had been running longer, so it was always gonna have a bigger audience, but I saw it as a goal to shoot for that was potentially achievable for me.
Trying to figure out who's better or worse than you IN COMICS IN GENERAL is a fool's errand I think and can get pretty silly if you step outside genres ("why is this slice of life doing so much better than my historical fiction when their drawings are less technically skilled!!!"), but I think it can be helpful to find the people who are like, executing the sort of thing that you want to execute at what feels like an achievable level!!
(unrelated p.s., niah holy crap, that is a heck of a compliment, thank you so much gosh!! ;o; )
But honestly, as far as original topic goes, I think it's also important to remember that like.... there are TONS of these threads. There are a lot of thoughtful posts, especially when there's a tangible and identifiable issue... but thoughtful people do not have time to develop customised strategies for every single creator that posts "aaaaa how to get more subs!!!" We give out the Standard Starter Advice a lot because, well, there's a lot of people who need the Standard Starter Advice.
If you want something more than that, then I think that it's kinda similar to asking for critique. If you just say "hey read my comic what do you think" you'll get a way less satisfying response than if you think hard about your comic and what your struggles are and post "hey, I'm unsure if my plot makes sense and I've gotten some confused readers, is it actually unclear? what can I do to make it clearer?"
In the same way, if you're looking for in-depth thought, I think you have to take the initiative to ask thoughtful questions. "I'm doing historical fiction horror comics, which I know is a little outside the mainstream, and after finishing my first chapter I want to start expanding my audience -- I'm active on social media and participate here on the forums, but are there any other steps I can take in general? And does anyone have experience with these genres or spaces that might be looking for the kind of stuff I make?" is going to get more specific thought than "I finished chapter one and I still only have 20 subs, is this normal?? what do I do????