There's probably nothing cheaper than an idea.
Truth be told, I'm not a particular fan of ideas. They are one of the most necessary things you want to have in your engineering team, but ideas need to be carefully managed. They should operate in a space somewhere between problems and actual solutions. They're glueing two spaces together. But let's talk about problems first.
Whether it's something wrong in your codebase or something wrong with your product - there's a high chance that you have stuff that can be improved. Finding valuable things to focus attention to is a delicate and rewarding activity, and ideally it leads to some shared understanding of what problems your team ideally is focusing on. Personally, I found it rather valuable to spend time on discussing the problems the team observes, sharing knowledge about how we perceive impact and importance of certain aspects. A shared understanding of a problem space guides ideas - which can be a good thing.
What's an idea? An initial spark that might lead to a solution for some kind of a problem. "We might be better off looking at a NoSQL database for our object cache" is an idea. It's not a refined solution, but it's an approach on how to (potentially) tackle an ideally understood problem. And the fact that ideas are not yet bound by the real-world details that have to inform and influence the final solution is what makes them powerful - ideas are where you want to think big. It's also what makes ideas nothing more than rough directional aids - they are, or at least can be, far out there, making them not immediately applicable.
Where the value lies is in converting ideas into applicable solutions. Execution matters is a two-word combo you probably heard before, and it's true. Ideas are cheap, the magic is in executing. And in order to able to do so, you need to shape a solution. And then build that solution.
When you're high above the clouds in your ideation phase, it's easy to skim over real concerns or cut corners that shouldn't be cut when going live. Like wearing brand new sneakers for the first time, there's a moment when you have to commit to actually confronting the new nice thing with the constraints of the real world - and this is where the complicated decisions will have to be made. Deciding for NoSQL is simple, choosing a specific product, implementing that, weighing the differences and so on, this is hard. This is decisions that matter going forward, and they are both more impactful and less forgiving than dreaming about the next castle in the sky.
Ideas are nothing but glue - they are cheap, discardable, and anyone can have them. Value is in solutions to problems that actually exist. Don't discuss ideas. Discuss problems, discuss solutions, but see ideas for what they are. Glue for more important things. It's about building, not dreaming.