I have been configuring the PCs in my work environment with SSD/HD combinations for some time. On the one hand, applications are Office packages, on the other physical-chemical simulation and analysis software. OS and applications go on the SSD. Data from the office applications and the final results of the simulations and analyses end up on the HD, intermediate results of the simulations and analyses on the SSD. I would run games, like all applications, from the SSD. With an SSD, the OS and the applications load very quickly, especially if they are made up of many modules, as is usually the case. HDs are slow when frequently accessing many small files, but they perform better when loading large image or video files, as long as the disk is not heavily fragmented. The latter naturally does not occur with SSDs. On the other hand, it is easier to recover data from HD after bad crashes (theoretically, backups exist, but this is often an illusion).

I also have the combination 1TB nvme SSD and 6TB WD Black hard disk - I am very satisfied. The fact is that large SSDs are not really affordable yet, which is why I opted for the combination. Would do it again :-)

Hello DarthShadow,
Well, I don't presume to make a general recommendation, but I can say that this is exactly how I have it in operation and I am very satisfied with this combination! (OS on SSD, data (music/video almost 3TB) on WD Black) But it depends mainly on the space required for data and thus on the budget.
I cannot confirm the loudness that is criticised by some users. Perhaps I'm just lucky...