Google's experimental quantum computer has been used to build logical qubits using up to 21 physical qubits.
However "The team believes that mature quantum computers will need 1000 qubits to make each logical qubit – Sycamore currently has just 54 physical qubits."
(A "mature quantum computers" is one where the fault tolerance is high enough for it to be generally useful outside experimental settings)
A logical qubit is by definition one which has a low enough error rate to preform quantum computations. That article is misleadingly using the term "logical qubits" to refer to a grouping of physical qubits which merely attempts to reduce the error rate. The resulting rate is still too high to perform computations so it cannot, yet, be called a logical qubit in the accepted sense.
“A somewhat similar story can be traced back to the 13th century when Nasreddin Hodja made a proposal to teach his donkey to read and obtained a 10-year grant from the local Sultan. For his first report he put breadcrumbs between the pages of a big book, and demonstrated the donkey turning the pages with his hoofs. This was a promising first step in the right direction. Nasreddin was a wise but simple man, so when asked by friends how he hopes to accomplish his goal, he answered: “My dear fellows, before ten years are up, either I will die or the Sultan will die. Or else, the donkey will die.”
Had he the modern degree of sophistication, he could say, first, that there is no theorem forbidding donkeys to read. And, since this does not contradict any known fundamental principles, the failure to achieve this goal would reveal new laws of Nature. So, it is a win-win strategy: either the donkey learns to read, or new laws will be discovered.”
