This is way off base. The 1911 was a US service weapon for decades. Of course it is a standardized platform! There is a milspec 1911 standard, and milspec parts are drop-in interchangeable. Exactly like ARs.
Now, many of the companies people are endorsing have decided to move away from milspec. So, if you choose to buy one of those, then you will be tied to custom parts and gunsmiths for modifications. But the same can be said of ARs.
Really?
Let's see, 1911 regular barrel vs. bull barrel. Not a drop in replacement from slide to slide. AR15's...........drop in replacement.
Fitting the 1911 barrel to the front bushing. Fitting the 1911 front bushing to the slide and to the barrel. 1911 handguards. pretty much drop in replacement.
Drop in 10-8 extended slide release did not fit on my friend's Springfield. AR15 throw in different charging handles, battery assist devices, ambi releases, buffers, etc.
Try fitting any number of the myriad parts from a 1911 from one maker to another and you need fitting............example Ed Brown, to Nighthawk, to Les Baer, to Wilson, etc......you aren't just dropping in a main spring housing, beavertail, etc. Even triggers need some minor fitment. Heck there are even different cuts for the sights that you intend on putting on a 1911 slide.
The list goes on and on and on............1911 platform is infamous for needing additional fitment to get the parts to fit and work properly.............exception might be something like the Taurus 1911's where the fitment and finish is so poor that there could be enough gap to get the new parts in there.
You will notice I said nothing about a milspec 1911. OP is asking about changing parts out and it would be a disservice to tell him everything is hunky dory and all parts will fit because that is not true.