Let's look at another aspect of the general computational enthusiasm that we're seeing in drug discovery these days. As you read my opinions, though, keep in mind that I've seen several cycles of this over a >30 year career, so I can't help but be informed (or perhaps misinformed?) by that experience. But not many of us have had thirty years of thinking about the subject of this press release from Novo Nordisk, which announces their foray into quantum computing.
This part of the blog post is where the background on that concept should go, but I'm manifestly unquanlified to deliver it. Broadly put, it's easy enough to define - this is the application to computational methods of the phenomena that can only occur meaningfully down at the quantum level, things like entanglement, superposition, and interference. There's no one thing that encompasses all the possible techniques of quantum computing (as far as I know!) but all of the proposals plan to use these effects to do things that simply can't be accomplished out here in the bulky world. You hear an awful lot of hand-waving talk about that step, stuff about "doing all the computations at once" and so on, and from what I do know about the subject you'd be better off ignoring that. But it does seem certain that quantum-based algorithms exist (or can exist) that would provide remarkable advantages over what can be accomplished classically. You're not breaking out of the Church-Turing thesis, though: anything that a non-quantum computer can accomplish, theoretically, can be accomplished by a quantum one (of whatever sort), and vice versa. But there are opportunities for huge accelerations in how quickly those results can be obtained.
Actually realizing those advantages, though - that's been hard. There was a claim of "quantum supremacy" from Google not too long ago (a result that was obtained far more efficiently than any classical system could have), but not everyone in the field believed that, to put it lightly, and recent results bear out that skepticism. Building the hardware for a working quantum computer is extremely difficult, as is keeping it working once you've built it. And no matter how well you build it, you're going to have to deal with quantum decoherence: the idealized particle-in-a-box of quantum chemistry courses can sit there platonically and not interact with its environment, but that's not what's going out here in the real world, particularly the real world where you'd like to read out the states of all these qubits at the end of the process. You will gradually (or maybe not so gradually) lose the specialness of the quantum states that you have gone to such trouble to obtain, so a big part of any working quantum computer is going to be some really robust error correction techniques.