amd graphics cards are generally not that good for this type of work
nvidia has the edge in this department .
when it comes to rtx 5070 vs 5060Ti 16gb i would take the 5070 any time .
it will be much faster in the vast majority of tasks
the instances in which you may run out of VRAM may
not even occur (depending on the type of work)
or will be to few and far between to be considered an issue.
RTX 5070 is just a more robust chip - it has 6144 cuda cores vs 4608 on the 5060ti ,
it has almost double the amount of ROPS (80 vs 48), 192 TMUS vs 144
it also has higher memory bandwidth (672 GB/s vs 448 GB/s)
this will result in much better raw performance and the extra 4gb of VRAM will not make up for it ...
as you can see when it comes to premier pro , unreal engine , daVinci , blender and after effects
12gb rtx 5070 has no issues holding up and it is beating an old high end
like rtx 3090Ti which has double the VRAM demostrating that the amount of VRAM is not the main factor .
in some cases it is on par or even better than rtx 4080 .
when it comes to nuke rtx 5070 is straight up recommended .
in marvelous designer you are not adviced to use your gpu that much anyway and you will get
much better results using the CPU as your primary tool .
substance 3D is about the only program out of all that you have listed
in which you could potentially run into more VRAM issues
since 16gb of VRAM is recommended -
but even still i doubt it will be an issue most of the time
(again depending on the complexity of your projects) .