The point of this thread is probably long gone, but I'll answer the question in the heading and chime in on my experiences on my grievances shooting both MFT and FF.
First the answer to the great question: I take great pride in being moderately bonkers.
Then to the meat of things: I've been shooting full frame longer than MFT. It's affordable FF that first got me back to doing photography since the film days and my medium format stuff were long gone. January this year after long pondering I pulled the trigger and got me a Panasonic GX80 along with the pancake zoom and a 25/1.7 that was on sale for not much money from a local dealer. I think I paid 478€ for the kit. Less than my RF 35/1.8, that is.
Initially this was an experiment for me. I wanted to try if having a smaller sidekick camera would make me have it with me more often. I didn't know what to expect IQ wise. What I did know was that my usual landscape bag weighed in at 8kg with the tripod, and taking that with me was always a deliberate choice. So something smaller and lighter was what I wanted, and not wanting to pay Fuji prices for lenses (again), MFT made the most sense. Something to fit in my surplus army field jacket pocket in a pinch was what I wanted.
Now some six thousand images later on the Panasonic I've two major grievances with it. One of them is the viewfinder, which has nothing to do with the overall system. The second one is the biggest IQ difference I've found between MFT and FF. And that's overall tonality or tonal depth if you will. The jump in resolution between the 16mpix Panny and my 30mpix Canon isn't that big of a deal, really. But the tonality difference is big, even shooting landscapes with base ISO. That means I have to work really hard sometimes with the Panny images to get the look that I want in post processing. With the Canon, the colours and tonality take much less work usually.
Still, I have printed images taken with the Panny and hung them on my walls. And to be honest, if you don't know the difference, you probably won't notice it. But it's something that frustrates me sometimes.
That being said, the GX80 paired with the 12-60 f/3.5-5.6 weighs about the same as my Canon RF 24-105 f/4 L alone. And having just added the numbers, I've used about the same amount of money on my complete MFT system as I have on that single L-lens. And that includes the GX80 body, the 12-32mm pancake zoom, Lumix 25/1.7, Lumix 20/1.7, M.Zuiko 45/1.8, M.Zuiko 9-18mm and Lumix G 12-60mm.
Hmm... That could otherwise be a reasonable proposition, but I just finished hauling my vinyl LP's upstairs in our new house, and I'd hate to do that again so soon... A box full of LP's is surprisingly heavy.
And if I were to move abroad, I'd go to UK or Denmark. I'm envious of their fogs. I'm also a bit envious of the lens choices Sony users have (I've been suffering a fit of serious GAS here)...