It could be Austin, as the above poster says, but in my opinion it's not. Kane has had a lot of "close but no cigar" situations in the Rumble and has never won, sure, you're absolutely right. But you have to take everything into consideration and with 11 consecutive years, most of which he actually has a pretty good run, half of which he's one of the final superstars left, will likely have the most eliminations in Rumble history by the time he's retired, and record for most in a year, and Kane has been the most consistent Rumble superstar in history.
If it's based on wins, sure it's Austin. I just go with Kane for other reasons. That's why we've got a forum and that's why we've all got our own opinions.
Since I'm a hockey fan, I'll equate it to that. Let's say Joe Thornton won 3 scoring titles in 5 years, and then over the next 6, never even competed again. At the same time, let's say Jaromir Jagr never actually won a scoring title, but has been in the hunt for one in 11 straight years and has finished top 5 in the league in points every 2 or 3 years. That's consistency.
Austin was the most DOMINANT star in WWE history in my view. But it's hard for me to go with Austin because he hasn't competed in years, when Kane, amongst several other guys have. Austin had a dominant 4 years in WWE. Kane had 1 dominant year, brief dominant stretches over the course of other years, and has always at least been consistently involved in feuds and on TV and almost every single PPV for 11 years.
Now, not saying Kane is Austin, but all these little comparisons are just to demonstrate where my opinion comes from, at least on the Rumble front.
Austin and Rock are the two most successful stars ever in my book. They did what other legends did in just 5 years and they did it when it was harder to acheive things such as titles and main events because there was one title and one WM main event.