Background
Normal guitars have strings that fan out somewhat towards the bridge. There can be as much as a centimetre's overall difference between the width at the nut and the width at the bridge. I presume this is mostly traditional. As I understand it, it may be because people originally plucked strings with their fingertips and the fingers had to be able to get in between the strings.
Nowadays we use fingernails and picks of all kinds. It seems sensible to remove this restriction. My guess is that it will make picking between strings much faster if we have strictly parallel strings with a narrower bridge. Also left-hand fingering of chords would have to change less as the strings wouldn't space out
Question
Apart perhaps from Hawaiian types of guitar, has anyone ever made a parallel-stringed guitar? Are they available for sale?
Are there any disadvantages?
NOTES
I am an experienced guitarist and have played classical, electric and bass guitars for many years.
Most classical players use their nails these days (I'm one). Also the strings on a classical guitar are more widely space at the nut than say electric. There should be plenty of plucking room.
I intend to suggest this idea to manufacturers. In addition to having a question, I am publishing this idea here. If I have invented the idea of a parallel-stringed guitar, I don't want anyone to patent it (including me). I believe all such innovations should be free for all to experiment with. I do not want any financial remuneration for myself if this turns out to be a good idea. I just want to see if if has been tried or will be tried. This would apply to classical, acoustic, and electric guitars.