Equity markets in most jurisdictions have a consolidated view: a single official price, a single volume figure, rules about where trades must be reported. Crypto has none of that. An asset trades on dozens of venues simultaneously, each with its own book, its own price and its own participants.
What this breaks
Volume becomes ambiguous, because the total depends entirely on which venues were counted and how much of the reported activity is real. Depth becomes misleading if summed, because the same capital is frequently posted in several places.
Even price is ambiguous at the margin. Venues differ by small amounts constantly and by large amounts during stress, which is precisely when you want to know what the price was.
Why the differences persist
Arbitrage closes gaps but not instantly and not for free. Capital has to be positioned on both venues in advance, withdrawals take time, and some venues are hard to reach for regulatory or practical reasons. Persistent spreads between venues are usually telling you about those frictions rather than about the asset.
What this means for reading structure
Venue-level is the honest unit. Funding is a per-venue fact. Open interest is a per-venue fact. Depth is a per-venue fact, and the only one that matters to you is the venue you can actually trade on.
A blended figure is not necessarily useless, but it needs to be labelled as a blend with the components visible, because the interesting information is usually in the disagreement rather than the average.
Where concentration helps
Options are the exception: liquidity is concentrated enough that one venue carries most of the meaningful book. That makes crypto options structure easier to read honestly than perp structure, which is scattered across many venues that each matter a little.