Generally speaking, your work must fit within a value stream - that is, to support your job/function you must do something that's rewarding (someone's got to pay the bills). There are a lot of interesting agile principles at play here but ultimately they revolve around delivery which must occur regardless of how complete, incomplete, fast, slow and/or viable your data is. Delivery is valuable. Your tech leads are the ones most clued up on what must happen and which compromises are acceptable. Their role is to get some data - any data - out so that you can make a qualified success of your product. Cutting corners and managing/deferring difficult decisions is part of that job.
Over time the cadence of features and the complexities of your data will require pivots. Initially you might have gotten away with simple line-level data but with maturity and agile planning the next revenue producing feature might require aggregation and complex transformations. Once again your role is at odds with delivery - if there's a simple way to make the end result a qualified success in the shortest lead time possible, data comprises ought to prevail over your immediate happiness.
Now with that said you might be thinking "wtf this is nuts - it can't be right... I'll never succeed". That's actually quite possible. It's often a reason why most developers move on. When that happens the process becomes self-destructive - new devs start and become disillusioned and leave creating an air of futility; product knowledge is virtually non-existent...all past decisions were shit and should never have been done that way in the first place etc.
So how do you fix this? I'm going to avoid the technical side because I don't know your stack. The procedural/operational solution comes from understanding and managing your employer's approach to agile. The big word here is Trust. Is your team trusted to manage the work items that enter the sprint? Are you trusted to add work items to the backlog? As developers do you own the sprint? Have you created items that address your technical concerns with concrete examples (it might take you several sprints to fully flesh these out)? If you answer 'no' to any of these it's time to address them and start owning the process. If you've tried this or you've failed to explain from a delivery perspective why you have problems and what their risk is (use past examples rather than future commitments) and there's been no traction you should consider quitting.