The genre has really moved beyond the classic formula. If you're tired of optimizing the same strategy over and over, a change of scenery will definitely help. I got stuck in a similar situation with one game series a few years back, and when I finally switched, I realized I'd just gotten used to one mechanic and forgotten how exciting it is to discover something new.
What's interesting is what happened in deck-building specifically: if Dominion was about building your own engine in a vacuum, the new games added interaction, asymmetry, direct confrontation. For example, there are games where you're not just trying to assemble the best deck compared to everyone else, but where enemies actively mess with your plans in real time, or where the cards on the table change depending on what your opponents take. That's a different puzzle altogether.
Anything like games with roguelike elements mixed in, or where deck-building is tied to a specific scenario, will give you a totally different experience than seven years of just Dominion. Try reading the rules for a couple of games that sound interesting, and pay attention specifically to how they change the basic principle of deck-building, not just add some theme to the packaging.