I think it's fascinating that we can at the same time hold things like "one is none" to be true, or that you should write tests first, but with science we already got so used to a lack of discipline that we just declare it fine.
It's not hard to not climb a tower you can't get down from. It's the default, actually. You start with something small where you can describe everything that goes into replicating it. Then you replicate it yourself, based on your own instructions. Before that, you don't bother anyone else with it. Once that is done, and others can replicate as well, it "actually exists".
And if that means the majority of stuff has to be thrown out, I'd suggest doing that sooner rather than later, instead of just accumulating scientific debt.