Try this on your chin: Shave left to right and right to left, swapping hands if you can. Grab the skin on your jaw with the free hand and pull back to stretch the skin. Go slow and take it easy and you should get a good shave around the end of your chin. Then, shave from the lower lip down to your clean chin, and do your neck as usual. I've seen people shave from the lower lip down and completely around the chin. I've seen it but I can't do it.

Good prep and maybe a hot towel can also help around the chin.

As for why people gave up on straights, just read Gillette's history. They sold razors cheap and made thier money on disposible blades. If you stay away from those multiblade razors they sell now, a double edge razor with disposible blades is still a good way to wet shave and not very expensive.

IMO straights are making a comeback more for asthetic and historic reasons, and it also turns your shave into a pleasant ritual. My electric is in a drawer somewhere, and I use a DE when I'm in a hurry. It's just fun smearing lather all over your face.