Ammeter bypass turning over alternator
This issue here is the proof in pudding.
@kewen300 followed this popular advice. Look what happened.
And now I'm the only one helping him.
The problem wasn't the ammeter.
Ammeters were used because they could be made small, relatively robust and were not too expensive.
They were standard on vehicles for decades.

They continued to be a popular aftermarket product well into the 1970s for cars and trucks did not have them.
This gage set may be from the early 1980s.

Here's another
Chevy and others didn't supply much instrumentation on their basic models. They saw their owners less as 'drivers' and more as operators who just wanted the car to start and go where they drove. They got a fuel gage, IIRC a temperature gage, and the rest was warning lights (aka idiot lights). Only Chevy products and GM's divisions that targetted 'drivers' got full instrumentation.
The development of cheap, robust, small voltmeters that could be put in vehicles seems to have begun mid-1980s. Sometimes we forget how good we have it now in terms of affordable handheld multimeters.