No, he is correct. Alot of embedded software uses a more complex form of that exact technique that he is shown in the code.
You technically can have a dedicated timer interrupt for every task but there are usually alot more tasks than HW timers, so instead they use a dedicated HW timer for time-keeping and use that as reference for all other tasks.
Exactly. IF there is operating system used (it's not always needed), programmers implement separate OS tasks. For simpler systems (like just reading some sensors) real time os is not needed, then such loops are implemented as a template (with much more error checking and restarting). Typically that "wait for tick" function just waits until hardware timer sets overflow flag (not even full interrupt), and this is done to have simple, easy to reason about system.
You technically can have a dedicated timer interrupt for every task but there are usually alot more tasks than HW timers, so instead they use a dedicated HW timer for time-keeping and use that as reference for all other tasks.