This is OT as it is not directly a Windows problem.

Old computers in the tower style have ample spaces in the case to add
another drive.

I don't see many new/current computers, but my impression is they are
styled, and only have a CD or DVD drive installed. When I see used ones,
the owners never thought to order a floppy drive installed.

I would want the flexibility to later add a floppy drive, and another CD
drive. etc. But unless in the original order, these modern cases don't seem
to come with spare slots for additions?

Is this correct?

TIA