No doubt, they made advanced technology, but they've been around for at least around 50 million years, and the zenith of their technology is kind of sucky. Sure they made city-ships and very advanced battleships, but compared to the Asgard, which have have a "recorded history of 200,000 years", they really seem to have had a very, very, verrry slow technological growth. For comparison, humanity literally evolved from rats to becoming an interstellar species in that time, yet the Ancients barely inched along their technological path for millions of years. Its honestly surprising that the Ancients havent just evolved quicker than their technological growth at the snails pace they advance at. Maybe the Ancients we know (human form) only evolved relatively recently (5-10 millon years ago), and had a different humanoid bodyplan beforehand, and technologically advanced and regressed due to wars multiple times before, but that would be the only logical explanation to why they cant seem to advance at all.