As someone who does a lot of illustration (and actually prefers it to making comics) I'd like to add to this:
Yeah, it's probably easier to get someone to want to look at your art than to get them to want to look at your comic. But doing standalone art isn't exactly easy street either...especially when you're stuck in that 'middle ground', where people like your art but just not enough.
They'll request free things from you even when you explicitly ask them not to, but no one will actually buy anything from you (no matter how low your prices are...). They'll 'like' your art, but they won't share it with anyone or talk to anyone about you. Growing your audience becomes like pulling teeth, and if you feel like you're in a good place with your art style it just makes it worse, because then there's nothing you can really do to try to improve your situation.
That's why a little story every once in a while, comics included, actually helps a lot. Even something as small as a recurring OC that people will recognize can do a lot to help stave off stagnation, if you're not fortunate enough to be one of those miracle-tier artists that just happen to have exactly what the people want these days.