I think we need to define what we mean by "Intelligent Life".
If we simply mean one or more of the following attributes, then I think yes, the rise of intelligence is an almost inevitable consequence of evolution (given a planet with a reasonably stable environment for sufficient time - like a few billion years!), as these attributes clearly confer an advantage over others:
- The ability to think in abstract terms;
Analyse a scenario which has not been encountered before;
Draw inferences and make predictions based upon incomplete information;
Make plans for future actions and expected consequences, including how others will respond to one's actions;
Tool making;
A sense of "self";
Communicate one's thinking to others of the same species.
Creatures with at least some of the above attributes have arisen independently multiple times on Earth - octopus, crows, dolphins, great apes (including humans), etc.
However, if we mean ALL of the above attributes, plus "Culture" and "Technology", then I suspect "Technological Intelligent Life" is much rarer - it has only arisen once on Earth in over 4 billion years.
One factor is that while emerging intelligence can clearly be an advantage over other creatures that might be competing for the same ecological niche, it is not a guarantee of survival of the species - early humans could very easily have been wiped out by any number of less intelligent life forms, including another hominid (look at what happened to the Neanderthals - it is thought that they were at least as intelligent as early Homo Sapiens, if not more so), sabre-toothed tigers, or bacteria and viruses - or ecological catastrophe.
Conversely, if a species is successful in its niche (it may not have any competitors or predators, for example), then there is no "evolutionary pressure" to "advance" the species, and the species can remain essentially unchanged for very long periods of time. Lions have been around longer than humans - but they haven't developed language or tools (thankfully!)
Think of the Age of the Dinosaurs - there is plenty of evidence that some of the later dinosaurs were at least as intelligent as modern birds - and yet in tens of millions of years, none of them advanced beyond something akin to basic bird-like intelligence. We don't even know if any of them had the capability of basic tool-making, which the modern crow certainly does have.