Candy Crush is a match-3 game. There are thousands if not millions of match-3 games out there. There are also match-2 games. They are all variations of the same theme - and the makers of candy Crush were not the first. I'm not sure where the concept started, but it was around long before mobile games - mobile smart phones - were even a thing. I think Bejewelled by PopCap was one of the early popular releases in the genre.
If you're making a match-3 game, please go ahead.
If you're making a candy-themed match 3 game and your graphics look like Candy Crush, then you may need to reconsider and change your graphics to something else.
The thing with games like Candy Crush on mobile is they capture their audience, and get them to just play their game. They release new levels etc. every few days. They have gimmicks to retain their audience. If you're designing for mobile you may struggle to break into that market.
On the PC casual game side, where match-3 is very popular, people often release a game say with 60 levels for someone to play (often with a story line). And they will perhaps play the game once or twice and then buy / find the next game. That creates a market for these games.