You're right, the number of participants are increasing and their artworks are indeed amazing so it's a bit hard now to win. But of course nothing is impossible and if you love what you're doing, you can execute a nice artwork since it's your passion. It would be better to just have less expectation to win so you won't be too affected just incase your artwork is not chosen. But atleast you did your best and you showed your talent.
The growth of art contest is good result for Roobet. More participants means more noise and free advertisement from participants about Roobet. However, they did not abuse participants and it is a win-win cooperation. Roobet will be exposed to more people from artists to cryptocurrency enthusiasts and gamblers. Participants will do have chances to earn great prize from contest and they also will be able to rank up by receiving a lot of merits for their art submissions in contest.
participants would provably do back tracking of what the past winners submission to have basis to create more better artwork to submit.
No better ways to learn from the best and in Roobet contests, from winners of their previous contests.
From past winners and their arts, you can learn about their ideas, styles and what are most favorite styles by Roobet and art contest manager. I don't mean copy same art style will make you a winner as each contest will have special requirements and themes for participants but at least you can learn general things from past awarded arts.