Evolution of bulge and disc masses and their corresponding mass fractions for the three galaxy samples, shown in bins of total galaxy stellar mass and separated by whether the galaxies experienced at least one major merger at z < 2. Each bin contains at least six galaxies, except for BD galaxies with major mergers in the low stellar mass bin, which includes only two. Solid lines represent the median values, while shaded regions indicate the 20^th − 80^th percentile range. BL galaxies tend to build their thin discs at later times compared to BD galaxies, which exhibit a decline in disc mass over time. In high-mass BL systems, disc structures may be temporarily disrupted by mergers but typically recover at later stages.