This is such a goofy assumption. That any life on Titan would use the exact same amino acids as earth-based life. If you have no clue whether something is possible, sometimes it's better to predict nothing at all.
I believe that the search for alien life is subordinate to the search for things that will sustain human life and/or industry, as we expand further outwards.
Most scientists and engineers don’t actually expect to encounter significant alien life in our solar system, and it’s merely a meme they use to tease middle-schoolers, Senators, CEOs, and naïve newspaper readers. Searching and discovering life forms would be really really fraught with terror and doom, if we indeed expected to find it when we looked.
Any natural resource that exists on a moon of Jupiter, or of Saturn or in the Asteroid Belt, and if we can exploit it and extract it and turn it into something useful, for example refueling, or life support, or repairing existing vehicles en route, or simply dragging raw materials back down the gravity well to Earth, then that is a natural resource we’ll want to investigate as we expand. Dyson spheres won’t be built in a day, but we’ll need a good start on the resource extractions real soon now.
This is the quiet part they won’t say out loud, because it’s much more exciting and non-threatening to say we’re looking for alien life forms rather than sustaining our own self-interest. But it’s all about self-interest when it comes to humans.