Almost every place that has a projector also has an HDMI cable installed.

I haven't used a CF card in the last 10 years or so, but SD cards show up frequently. (Cameras, Rasberry Pi, Prusa 3D printers). For the Raspberry Pi I needed to use an adaptor because it uses smaller cards, but still better than no card reader at all.

But of course that's just my experience. If you use CF a lot, an SD slot won't help.

Any projector setup worth having would have an HDMI cable ready for you.

A 5.25" floppy diskette won't fit an a CompactFlash slot.

What's your point? I can come up with silly excuses too.