Catalysis lowers the activation barrier, sure, but you still have to contend with the thermodynamic equilibrium in the absence of the catalyst, in addition to subsequent degradation by light, etc.
> ocean full or random stuff that we can't actually imagine today
We probably can't ever really know what was in the Earth's ocean before life, but quite a bit of research has been put into figuring out some plausible conditions and then testing the hypothesised pathways put forward by the leading theories under said conditions.
All this is to say, yes, clearly abiogenesis occurred, but there are major gaps in the leading theories that are interesting and testable. I don't think it's very useful to gloss over the details, even if in the end the best we can hope for is a plausible pathway given a specific set of assumed conditions.
Is catalysis always symmetric? Or do some catalysts only work in one direction?
I imagine one that splits a molecule could work only or mostly in the one direction, if to go the other way would require both constituent parts to come together at the same time. But that is an example favoring entropy.
What would one that favors assembling molecules look like? A ribosome seems like the extreme example; those don't disassemble proteins. But is a much simpler example very unlikely?
The difference in entropy is so small that we are talking about entropy of dissolution. It's not hard on those conditions to introduce some element that weakly bias the reactions on a different way.
I don't want to minimize the gaps on our knowledge. We don't know how any macromolecule polymerization occurred. But I also don't want to maximize the gap. Those kinds of reaction are completely mundane and occur on a huge variety of environments. The fact that we don't know what environment it was doesn't mean it's an outwordly phenomenon. And adding just a few of those mundane reactions is enough for life to appear.
(Anyway, I question your certainty about the concentration of water on our primordial oceans. Abiogenesis research usually uses a model of water origins that gives a precise estimation for its amounts, but not only we know that this model is wrong - water is cycled by geologic means like any other mineral - but we also do not have anything with near that amount of precision to the other substances that composed it.)