If we want to discuss “what reality really is”, then we have to scrutinize what we in principle are searching. It leads to some kind of explanation in terms of some kind of smaller things in some kind of larger things engaged in some kind of process. If we scrutinize this principle, then we can understand that such an explanation just gives rise to new questions concerning what these kinds of things really are, and why the process is proceeding as it does. The question “what something really is” thus appears to split up along several lines instead of converge into a single answer.
The fundamental question is if it is possible to find out “what something really is”. One part of this question concerns the practical aspect that we can partition reality into different kinds of things in several different ways and then compare these different partitionings using different criteria, but a more fundamental part concerns the theoretical aspect of whether it is possible to partition anything into a consistent set of kinds of things. This latter part is what Russell’s paradox shows is impossible if we include time in the partitioning (ie, if we also partition it over time). We simply can’t partition anything into a consistent set of things if we also partition it over time. Any partitioning in time is simply inconsistent with every partitioning over time, because “in time” is orthogonal to “over time”. This fundamental part of the question thus makes finding out “what something really is” impossible, because “something” simply can’t be anything particular (if we include time in the consideration).
It thus isn’t even theoretically possible to find out “what something really is”, because everything can’t be anything particular.