The following was shot with an E-M1 Mark III, and I believe all of the photographer’s Iceland shots were taken in handheld-high-res mode (HHHR) and really worth a look. ISO 200 @ 1/25s. He even had a wave knock his camera off into the salt water. He just rinsed it off with bottled water and kept going. Camera and lens weighs about 2.5lbs.
I think M43 gets a bad rap from the review sites, as it’s often reviewed in light of how FF is better. M43 is a very capable platform. It may not be for everyone, but it does some things really, really well, and you can squeeze a lot out of it.
I have to use the High-Res mode on a tripod with my E-M5 Mk II, but the ability to play with perspective correction in camera was something else I forgot about Olympus innovating with too! I have used that so many times in place of a tilt-shift lens!
In my mind I don't really care if people have expendable income and want to have the best of the best cameras and lenses at their disposal, good luck to them. It's their life, they are free to do what they want in all regards. Will full-frame make better imagery? No. Potentially it can, if used to its best, but very few full-frame users do that.
People do tend to bang on about shallow depth of field being better on fullframe as compared to M43 as a justification for going to a bigger sensor. In all seriousness though, how many portrait photographers are shooting portraits with a 1mm depth of field? Just cause their cameras can do it, do they actually use that lens at f/1.2 for portraiture with the image resolving distortions and diffractions caused at that aperture? Not that many at the top end of that photographic field really. That f/1.2 lens is used at f/2 to f/4 for best resolving quality on the high MP full-frame sensors used.
There has been the ability to use Voigtlander f/0.95's forever with M43 bodies, so really, that 'lack of shallow depth of field' is a bit of a red-herring statement. Yes, the physics can achieve a slightly shallower depth of field on full-frame, but is it noticeable when presented on the interwebz? Honestly? Not really.
For the frugal minded folks, the purchase of a few cheap glassless macro-rings later and you have no image loss with stupidly shallow depth of field! I have so many images that satiate my cravings for shallow depth of field captured on the various M43 cameras I worked through over the last year and a half, in surreal landscapes, portraits, macro, and architecture. All captured without the use of stupidly shallow lenses and only a few times did I use the macro-rings. I think the widest lens was an f/2. If you know how to create that look, it can be achieved on almost any camera, including mobile phones with their tiny sensor & without going into Portrait mode.
I have said it before and I'll say it again, for my documentary film-making headshots in interviews, I favour the Blackmagic Pocket Cinema Camera with its lowly and ages old M43 sensor. I wouldn't use it for any action captures, but for talking heads and landscapes/establishing shots, it's the go to workhorse for me. Take some frames of the ColorChecker Video Card and it's dead easy to colour match to my Sony cameras.
My takeaway from all this is that you should feel free to have whatever equipment you want or need without feeling a need to have to justify that. I had two participants in my Mindful Photography initiative that were able to buy the Nikon D750 & pro glass for it, but they still had issues with creating good quality imagery. That they had the expendable income to afford this is irrelevent, good luck to them! The potential is there for them both to eventually grow into using those mega-cameras and fingers crossed, they will one day.
Getting back on track, M43, like APS-C has evolved over the last few years to become a valid sensor format for many practicable purposes. That one partner of the format has been open (finally) about their financial woes and has taken steps to try and get some equilibrium again is good. I do wonder when we will see this from Canon and Nikon, as they have been riding multi-Billion US$ losses in the camera departments for many years too.