Felix definitely deserves to be a HOF IMO. If not him then what pitchers after Verlander, Scherzer, Kershaw will?
A couple of names that come to mind are Skubal and Skenes. Of course, given the fickle nature of pitchers today, each would probably have to establish a five or six-year period of dominance if their arms do in fact, ultimately betray them. That would be in line with someone like Sandy Koufax (God, is he really 90 years old now?), whose peak years were rather short, and didn't pitch past the age of 30, yet made it into the Hall on the first ballot in 1972.
If you put King Felix's career in the right context, then you could make a case for his induction. One comparison I've come across is Dizzy Dean, the last NL pitcher to win 30 games. For the first five years of his career, Dean was one of the best pitchers in baseball, but when his arm started to go bad in 1937, the rest of his career was a slog. Similarly, from 2009 to 2014, King Felix was the best pitcher in the American League by any number of metrics, but when he lost a yard of his fastball after that, he was just another pitcher.
I guess it's a matter of deciding if the earlier lights-out years outweigh the later mediocre ones.