Why are modern SLRs better camera bodies than the so-called classics?
One major reason is your classic manual focus camera is basically a shutter priority camera. You set the mechanical shutter speed dial on top to a set speed. Your aperture is virtually in "slave" mode since you adjust it accommodate your aperture setting. Nobody twirls around their shutter dial left and right to accomodate shutter settings. With a more modern electronic camera it's as easy to shoot in aperture priority as it is to shoot in shutter priority.
This is the last production consumer film camera made by a major camera manufacturer. Decades of R&D went into its design. It has electronics only dreamed of in the 50's., 60's, and 70's.
And they're neither trivial or frivolous (see above as one example). Electronics and CPUs helped eliminate much of the clockworks that wear over time. I know if my shutter is at 1/1000th, that's what it's shooting had not off be 1/2 a stop. I can see important information on the digital display on the top plate. I have sophisticated matrix metering. I can switch between modes easily. Another is seeing settings in the viewfinder and making adjustments from a thumbwheel without having to take my eye off the viewfinder.
It is much lighter than an OM1. It's shorter in length. It's a little taller due to built-in flash, absent on the OM1 and useful when you need it. It is a bit wider because it has a useful grip. Its ergos are better than the OM1.
You just have to get over the fact it's made from high quality plastic. Like your keyboard. Like your printer. Which you wouldn't really want made out of metal, would you? And like vast majority of lenses made today including very expensive high-quality ones.