Bumping this thread because I haven't seen anything yet, but people have gotten to the end of the game. In fact, here's the final cutscene in 4k.
This might be a Persona 4 situation where this game becomes playable sooner rather than later. Once it does, the entire franchise will be playable on PC at playable framerates in some form or another. Portable Ops still has a funky control scheme, but you can work around that by mapping the analog nub to the right stick and make that rotate the camera and use the left analog for movement and use △ or ⨉ to enable walking.
Aren't the HD Collection games also available on PS3? Or are the controls for the HD version of Peace Walker not improved in that port? I'm honestly surprised the HD collection hasn't gotten a PS4 version by now.
But yeah, concerning being able to play the series on PC... Last I checked, there's PC versions of MGS 1 and MGS 2, and I think both of them require fan patches to be more playable on modern machines. MGS3 and the PSP games have long been playable via emulator. And of course, MGS5 and Rising on PC. That just leaves MGS4, yeah.
And also Ghost Babel on Game Boy is easily emulated - while that's not a mainline title, it's still very much worth any Metal Gear fan's time.