>Canon
Ergonomics optimized for the use of large lenses. Caucasian skin tones have an orange shift. Confusing ergonomics for users of like, all other cameras. Historically and presently hideously expensive. Good tech support program if you pay for it. Only sony even comes close and theirs still sucks. Better video specs and framerates out of their sensors than others at the cost of some form of image quality hit. EF cameras would have weird purple bands in the noise, RF cameras apply noise reduction at low ISOs which softens the image slightly.
>Sony
Sony has been historically hit or miss on good cameras but consistently expensive so a lot of people hate them. The non-SLT DSLRs and A7 models III, C, and newer were all good. Sony/zeiss lenses are all terrible.
>Nikon
If canon fixed all their IQ issues in exchange for losing video specs, and used a control scheme more like everyone else. Boomers love them for their fairly accurate hues but unrealistic vibrance in the SOOC jpegs.
>Panasonic
Washing machine/camcorder company. They have good tech but are kind of retarded with releasing it in cameras. Recently came out with an ADC/Amp setup that brings a micro four thirds sensor within one stop of the ideal dynamic range of an ideal MFT sensor, once you re-adjust the charts for measured rather than labeled ISO (unadjusted it runs along the ideal line).
>Fuji
Fuji is a film company and makes bank off instax and photo paper. Their camera division has been overlooked because well, it's bad, unless you're a hipster, and love low IQ and bad ergonomics because that reminds you of 35mm film (reality: xtrans looks super digital, 35mm film cameras had DSLR-like ergos). The XH2 and XH2s might change that a little but fuji insists on using this xtrans CFA that resolves less detail than bayer for the same reason bayer resolves less detail than a leica monochrom, so take 30% off all your megapixel figures. A 30mp canon 90d takes sharper photos than a $2000 40mp xt5...