I work as a surgical tech for a living, so obvious bias on modifying the body - making that shit happen is my job! The medical applications are pretty wild - we can replace worn down bones with titanium replacements, or stick a diode in you and makes your heart beat at a specific rate, or replace the chambers in your dick with a manually filled balloon if you can't get it up anymore (legit, it's a thing [SFW - seriously]).

Guessing OP is more directed at non-medical applications; we (society in general) already mostly accept that on an aesthetic front - piercings, tattoos, etc, but we've only scratched the surface functionally.

You might be interested in the concept of "transhumanism" which is kinda the more sci-fi flavor of augmentation, but the better our tech gets, the less 'fi' it is.

Lots of cool ideas, like eye lens prosthetics capable of slapping a HUD on your field of view, or being able to chemically or electrically stimulate a specific part of the brain to pump up your alertness or w/e... how often those ideas manifest as an actual product, eh, mixed results (looking at Musk's disastrous neurolink garbage).

There's also simpler stuff - I saw a documentary on this stuff years ago, and one of the cool examples was a guy that got tiny little rare-earth magnets - little 1mm balls or thereabouts. Dude cut the ends of his fingers all the way down to muscle, and implanted a magnet ball into each one, sewed back up, and let them heal. So, now he can pick up ferrous objections with a poke; and cooler than that, unexpected result was he how has a sense of magnetism! Any time he entered a magnetic field, he could feel feedback from the implants, so he could tell the strength and polarity just by moving his hand through it. And apparently some things generate a magnetic field that you wouldn't expect - like he noticed feedback when he was cooking on the stove from those those heat coils: when it was on / hot it would move the implants slightly, so he had an extra layer of warning for things like when a coil is hot enough to burn skin but not quite 'red hot' because the magnetic feedback was more noticeable than the actual heat it was putting off.

I'm all for the concept. Definitely wouldn't recommend a DIY surgery like some of those folks do, but I could definitely see something like non-medical body mod clinics popping up the same way we have tattoo parlors now.

Pretty fascinating stuff!