It's possible that this machine needs a new belt

Not the original asker but oh boy I don't even know what to ask now! I'm recently really interested in vintage sewing machines and history of sewing machines but have a lot of difficulty finding more in depth info after reading as much as I can on singersewinginfo and ismacs. Is that the sorta stuff you know about too? My questions may be way off context sorry

Like do you know what ever happened to the knee control? It seems like it was once really popular based on my FB marketplace but now it's totally unheard of and somehow morphed into presser foot control instead of motor

Vintage all-metal domestic straight stitch machines have a reputation of being very hardy and can do almost anything you throw at them. Is the same true of all-metal zig zag machines? Does the added mechanical complexity for zigzag make a difference?

Is there anything to the hype/high prices of singer featherweight and Swiss zigzag attachment or is it just that they're small and cute?

Whatever happened to sharps needles? I thought microtex was the modern equivalent but they don't go up to 90/14 ime. Similarly are universal needles really "best" for general application or more "jack of all trades master of none"?

/r/sewing Thread Parent Link - imgur.com