Global transfers are slow because they generally undergo some form of manual review for risk and AML/KYC. Crypto is fast because it pretends that this isn't a requirement. That only works as long as it's small enough people don't care. Once people care, things will look a lot different than they do now.

There's no reason whatsoever that a crypto payment would be faster than a traditional payment - in fact, there's a ton of reasons the lower bound is much slower.

This is an intentional process decision, combined with some (replaceable) outdated technology. However, the former strictly dominates the latter.

Funnily enough my transferwise international payments are basically instant.

With Borderless/Multi-Currency it's even cooler, since it grants you local banking details in many different locales, so someone can pay you via ACH, FedWire, SEPA, EFT, etc and have that value reflected in your account almost immediately (depending on the transfer method) and (depending on the transfer method) without charge.

Isn't this convenience at the cost of trusting a third party, I.e. Transferwise, with your money? They can unilaterally hold, delay, or stop you from using your money.

Yes, that is true, however Wise is a heavily regulated entity (in the sense that they are regulated simultaneously by a number of global regulators). Broadly speaking they would have to have a very good reason - a legal one - to preclude you from accessing your money. The flip side is you have a legal pathway to recovering your value in the unlikely situation you describe. Pros and cons.