My tips on Robin MU would be trying not to go for air lasers for reasons mentioned, but a good read and robin can hit you out of the air with his long J1 which is actually a really far reaching jump normal.
Supes has negative wakeup options in this matchup pretty much but if you eat the D12 is doesn't lead into anything major for robin as D12xxTrait is punishable on block, D12xxDB3 (Swoop) has gaps in it that should be labbed, and D12xxDB2MB is just a waste of meter for robin. Of course he can stagger D12 with just D1 or start using other strings such as 212 once conditioned but that's just part of the matchup.
Things I would say though, although robin is pretty good at keeping superman honest with his trait pressure with his D12 and DP, superman is good at keeping robin on his toes in footsie range also. Robin has nearly no plus frames (123 is his only one) outside of trait which requires setup, so he can be checked with F23 after nearly everything. Superman's J1 can be a good tool for dealing with Robins using J3 or his air DB2, if read well, and his strings have a deceptive amount of recovery on whiff, even though whiffing them is quite hard.
Seems like a 5-5 to me. Superman can't zone robin out like a lot of other non-zoners characters do (Batman, beetle etc) and superman is kinda free on wakeup, but superman has pretty good options at dealing with robins normals. Grounded zoning with DB3 is also still relatively effective if mixed with ground laser to stop robin from throwing out birdarangs after each one. Also 90% sure there is some way to dodge birdarang using well timed jumps or air dashes, but I haven't seen anyone do it in ages online.