... over doing nothing ...
... initially.
Progress, over time, tends to involve both variation in routine and specific methods, progression, programming, modalities, techniques, form, movements, etc.
One somewhat dubious 10 week study of newbies, as many others have commented, doesn't communicate much.
A further complication is that much of the hypertrophic adaptation is systemic, that is, relates to overall body stimulus and other factors (nutrition, rest, genetics, etc.). Among those effects is the net hormonal response (testosterone, HGH, ILG
Heck, there's a well-known phenomenon called cross education* where an untrained limb will see strength / hypertrophy gains when its opposite is trained:
<https://en.wikipedia.org/wiki/Cross_education>
(Other / similar terms: Cross-Transfer Effect, Inter-Limb Transfer, Motor Cortex, Activation, Contralateral Training Effect).
Body adaptation to resistance training is weird.