We used to want to connect SSDs, hard drives and optical drives, all to SATA ports. Now, mainstream PCs only need one type of internal drive. Hard drives and optical drives are solidly out of the mainstream and have been for quite a while, so it's natural that motherboards don't need as many ports.
> Now, mainstream PCs only need one type of internal drive
More so it would only need one drive. ODD is dead for at least 10 years and most people never need another internal drive at all.