'Muscle confusion': do you really need to constantly switch up your program
The idea of 'muscle confusion' — constantly switching exercises and programs to 'surprise' the muscles and stop them from adapting — became popular through fitness programs selling variety as the main selling point. The problem is the term misrepresents how strength progress actually works: muscle and strength growth primarily depend on progressive overload — gradually increasing weight, reps, or volume on specific exercises over time — not on novelty for its own sake.
Switching exercises too often actively works against this: tracking progression and reliably increasing load requires sticking with the same core movements long enough to know if you're actually getting stronger — otherwise you're comparing yourself across different exercises every week with no baseline. Being a constant beginner at a given movement also burns part of your potential on learning technique instead of building strength within an already-grooved pattern.
That doesn't mean variety is bad — periodically changing accessory exercises and training emphasis genuinely helps long-term progress and motivation (see periodization). But the program's core lifts are better kept stable long enough to honestly track and deliver progressive overload, rather than swapped out every week for the sake of 'confusion' as an idea.