...and I would guess that your 2021 dial is pretty smooth.....when comparing to earlier watches.
I was fortunate to attend an event at the Miami Boutique where I had a chance to view and examine literally dozens of Tourbillon and Resonance watches of various generations spanning all 25 production years. The difference over time is undeniable and actually very visible...... especially if one has a benefit to compare MANY watches at once, side by side like I was fortunate to do.
1) The early (mostly brass models) have dials with most texture and corresponding shimmer.
2A) * Very early* Gold caliber models still had the same coarse dials.
2B) *Early (but not very early)* gold caliber models still had quite visible texture. As seen on my RG TN in the original post, as well as my Plat/WG RN (pictured here)
3) the exact year cannot be pinpointed here because it varies from one model to another ...but generally I have observed that sometimes in mid-2010s all dials became very smooth....i.e no nexture, no shimmer from lateral light.
I'm actually fortunate to confirm this observation personally. My brass RDM has a significantly coarse dial. My previous Plat/WG RN and the newly acquired RG TN still have nice texture but it is a little bit less than the brass models had.....and my UTC from 2015 as well as my Plat/Salmon RN (also pictured here, below) have very fine media blasted, super smooth dials (i.e no shimmer to speak of from a lateral light source)