Intelligence is Rare, and hard to evolve
Unfortunately evidence (ie. life on Earth) indicates intelligence is not inevitable.
The dinosaurs have been on this planet for 250 million years, and they never developed farming, cities, and technology.
Prior to that there were many billions of years where life existed, yet intelligent life capable of consistent invention, has not occurred.
Also, we have had the same brain size for quite some time (in fact, Neanderthals had larger brains than us), yet intelligence enough to 'invent things' is only evident in the last 40,000 years, when the secret of fire is discovered, or when farming was used. And that's when we were already on the planet for over 1.8 million years.
So why is this?
It is probably ironic, but it may be that our deficiencies as a species is a major factor in our intelligence, combined with extraordinary luck and being in the right place at the right time.
We have laughable attributes - we don't have much fur, don't run very fast, our digestive systems are fussy, our jaws and teeth not like predators, and our children are difficult to bring up and require inordinate resources. Yet, necessity is the mother of invention, and it may be that these deficiencies caused us to invent fire to keep warm eventually during the last ice age, use tools to defeat predators and be safe, have intricate social structures to protect vulnerable children, breed plants to farm crops to eat comfortably, and basically a very ponderous and slow trial and error process occurs through invention.
So in other words, the attributes of your archosaur may be insufficient to develop intelligence, and it may be too good at what it does to really need to develop social structures and trial and error technology. In a way, it may just be sheer luck that it develops intelligence enough to embark on invention, with the help of a lot of adversity.