  In this work, we explore the triangularity effects on turbulent transport
employing global gyrokinetic simulations performed with the ORB5 code. Numerous
experiments on the Tokamak \`a Configuration Variable (TCV) and, more recently,
on the DIII-D machine, have demonstrated superior confinement properties in
L-mode of negative triangularity (NT) over positive triangularity (PT)
configuration. This presents a particularly attractive scenario, as L-mode
operation eliminates or significantly mitigates the presence of hazardous
edge-localized modes (ELMs). However, a full theoretical understanding of all
these observations remains elusive. Specifically, questions remain about how NT
improvements can extend to the core where triangularity is very small, and
whether these improvements can scale to larger devices. This paper addresses
these two questions. Our analysis is divided into two parts: we first
demonstrate that the confinement enhancement in NT configurations arises from
the interdependent edge-core dynamics, and then we present the results of a
system size scan. Crucially, we find that the relative turbulent transport
reduction of NT over PT appears not to be contingent on machine dimensions or
fluctuation scales and is moreover robust with respect to variations in plasma
profiles. This insight underscores the fundamental nature of the NT confinement
advantage and paves the way for its potential application in future fusion
devices, regardless of their size.
