I agree with all of you that everyone has to judge what works for them.
I just remain completely surprised that after abandoning the format a few years ago I then did a complete about-face when I bought a GX8 and Lumix 12-35/2.8 in an Amazon January sale (in anticipation of getting the announced 100-400 for birding). What did it for me was a side by side test with my main kit at the time a Sony A7R and associated lenses.
What I discovered was at the pixel level up to iso800 I could not see any difference. Yes, there were more pixels in the 36mpx sensor but when I checked the actual definition of elements at 100% they was no difference to me except one was larger than the other.
Obviously, above iso800 there was a big difference due to noise.
What absolutely made a difference was the quality of the lenses. The Lumix 12-35/2.8 was considerably better than the Sony Zeiss 24-70/4 and for a lower price actually was a faster lens. The 35-100/2.8 is ten times (I exaggerate but a lot, lot better) better than the dreadful Sony G 70-200/4 which I owned for a week and then sent back (soft and mushy even stopped down and a heavy b*st*rd as well).
On Friday I walked about 3 miles around central London shooting photographs of monuments and statues for a friend. I carried by GX8, the 100-400 (which is great for statues, btw), 12-35/2.8 and 35-100/2.8 all in a small Think Tank backpack (and I mean small). To take the same lenses from, say, the Sony system would have been impossible - or at least not for a man of reasonable health but with legs entering the 7th decade of service.
Horses for courses. As I say, I am still as surprised as anyone that I can take photography which is suitable for mass distribution on a m43rds camera - but my body is very happy indeed.
Just my two cents
LouisB
PS Unfortunately, I do suffer from GAS. I would really like to buy back into Hasselblad MF film cameras but I think my back would finally give out one if I did.
PPS I'll be contraversial and say that the last men standing in the photography industry will be Panasonic, Olympus, Pentax and Fuji (the latter two for MF mirrorless). None of the FF mirrorless contenders offer much of an advantage of m4rds and Nikon and Canon are going to go bust unless they embrace mirrorless with backwards compatible offerings.