DIY grounds. Then clean/fix OE grounds.
Some OE grounds could be replace w/ heavier grounds when have a lot of stuff eating power like big sound systems.
Replace Braided ground(s) w/ same. This behave different and handle more power too. Braided ground(s) are Main Ground Path from Frame to Block and Alt Case.
If have crappy alt mounting hardware, clean that but do not lube most bolts. Only a bit of lube on the big bolt in the alt to stop "rusting" so can't replace a belt. Don't lube places where alt gets clamped by or hits brackets or will have belt problems.Why Remove?
DIY Grounds themselves are often poorly done.
Even if best parts are used, often leave OE grounds there and they maybe iffy to bad.Results?
In most cases, will have Too many grounds that can have Ground Loops causing problems.
Ground loops create they own circuits causing very high noise and other issues.
Or 1 bad ground wire act as antenna and noise out the system.
In Audio systems often hear this as a type of "Feedback" or Hum or 50 or 60Hz mains power buzzing that can be Very Hard to track down. In some cases can even hear AM radio from a station nearby. Can pick up FM etc too but sound like noise.
In "TV" cable and other systems w/ Coax Cable... Just one loose connection is enough to cause iffy ground even if the center wire make good connection. That iffy ground can slow down I-net to you to having problems for a whole neighborhood. (Many may see Cable Tech using an odd "wrench" to tighten cable ends. That is a Torque Wrench. Example: https://www.techtoolsupply....0lb-p/twaf-71620.htm