When I encounter this feeling, I don't channel it into 'I'm a failure', I channel it to 'I have more to learn'. That's when I kick into detective mode and try to spot things that they're doing (that I admire about them) and go after learning how to do it.
I've learned that beating myself up doesn't make things happen for me any quicker, it's not effective, STOP IT. It also make no sense to be angry at myself for not knowing how to do a thing [whatever it maybe that this other artist is excelling at].
Comparing yourself with other artists isn't logical, isn't practical, there is no good side to it unless you're doing it critically in which case you aren't beating yourself up, you're analyzing how to improve.
All of us are not created in a vacuum nor do we come from the same backgrounds. Each person has learned art differently and has had different experiences. It makes no sense with that in mind, to take what another artist has over me personally. I can achieve certain milestone levels by simply learning and doing. Doubt and jealous will only sour the process and impede progress. Don't compare yourself with others.
TLDR- Don't compare yourself with others. Don't compare yourself with others. Don't compare yourself with others.