One of the greatest advantages of mirrorless camera systems, as I see it, is the use of fully manual lenses from years past. The short lens flange to sensor distance of these cameras means that with what amounts to a metal tube, with appropriate mounts on each end, can act as an adapter for nearly any detachable lens ever made.
But why would you want to do that? Autofocus is immediately off the table and who wants to be bothered selecting their aperture with the hand they're now stuck using to focus with? Well, here's my take on it and if I could summarize it in a word, that word would be connection. There is just something about slowing down the process to a more deliberate pace that allows a deeper level of seeing. I cannot even hazard a guess as to how many times I've reconsidered a composition or focal point while working the metal rings of these relics. Now that 90% or more of my photos are shot via vintage lenses I literally never chimp. Furthermore the number of overall frames I trigger has been greatly reduced which helps quicken my post process.
Maybe you're not buying this. Possibly I'm romanticizing what's nothing more than a throwback to my youth. Here's the deal; an adapter is about $15 usd. You're probably using a 50/1.4 as a door stop. If you've already got a mirrorless body of any make I say give it a go. You may be amazed at what slowing down your process can do for your final image.