Yes, you did not write that 30 years ago!
There was no digital.
There were no serious cell phone cameras.
You can not do 810 for $5.00.
You can not easily dodge and burn 810 contact prints without substantial investment in a very sophisticated contact printer, and even then, it is not easy.
If 810 prints are your goal, it is a very small enlargement from 45.
Making 810 prints from 45 allows one to easily manipulate the image, if necessary or desired.
Lastly, 45 is infinitely more versatile, more convenient, less expensive, much lighter, unless you get a full blown, modular studio camera!
45 offers a vastly greater range of lenses from extreme wide angle to the longest focal length you could possibly use on most 810s to macro lenses.
Lastly you can do creative printing on 45 like cropping or changing ratios, simply and easily when enlarging.