Are you a biochemist? Would the Theranos machine have worked with new tests using new reagents? Is the needed blood volume not similar to, for example, payload capacity? Are we discriminating against people who affect an unusual voice?
Everyone in diagnostic medicine knows this (they've been dealing with this problem since the glucose finger prick test). That's why no biotech VC ever invested in Theranos and they had to get tech VCs and fancy board members like Henry Kissinger. A cursory glance at the proposal by someone qualified would have shut that down immediately, but tech VCs don't do due diligence anymore.
They hope they can cash out before the bubble bursts, whatever that bubble is.
That's also the entirety of the biotech VC industry, except even more so.
Biotech startups require far more capital to make it to market than tech startups, so biotech VCs take the role of early stage funding for R&D. Then the startup IPOs (with zero revenue and unlimited scientific risk) and uses that to fund its clinical trials, while the investors dump their stock. Then, because ramping up manufacturing and quality control takes even more money, the biotech startup sells out to a pharmaceutical company once its passed its trials or the results are promising enough to take the risk, closing the financing loop. Most of these startups stop existing before they even earn a single dollar in revenue, either because they fail or they're acquired by someone who can actually manufacture and distribute their product at scale. This has been the way of the industry for at least the last 20-30 years ever since the small molecule cliff hit like a brick wall.
So, the VC industry whose standard operating procedure is to unload companies onto public investors long before anyone even knows whether the drug or device would work, wouldn't touch Theranos with a thirty foot pole.
That's the point. As yet uninvented tests and reagents are the same kind of line of BS as "let's make the rocket bigger." While I have the advantage of having a mother who is an immunologist and did in fact work in developing diagnostics, all it really takes to call shenanigans is a knowledge of project management and critical path analysis. By the time you're launching 15 or 25 starship missions to refuel one on its way to the moon, the whole project is irrelevant.