My primary system for the past decade or so has been Sony E, and it's been quite a ride, seeing it evolve from lifestyle accessory into something more serious. It wouldn't surprise me if I'm still using my current A7-series camera a decade from now, and seeing as how I used my first-generation A7 for 7 years, I don't think that's too unrealistic. Did much agonizing and decided that the 3rd-gen models were really where the big advances took place: Olympus-derived IBIS, killer battery life thanks to NP-FZ100 battery, fast/silent operation and so on.
With Olympus, I found that I liked having the resolution-quadrupling, de-Bayer-ing pixel-shift feature, and that narrowed my Sony search down to A7R3 and A7R4. Only the latter offered resolution-quadrupling though. And killer Sony promotions in 2020 ultimately sealed the deal in favor of the "4".
I still get a definite sense of "holy cr@p!" when viewing the 4's images: Combination of no optical antialiasing with high resolution sensor means I can generally have my super-resolution cake and eat it too, with colorful aliasing artifacts tending to be negligible to mild. And if "mild" isn't enough, pixel-shifting can do away with it altogether.
But..? Need to exercise some self-control when shopping for lenses, as there's now a plethora of lenses offering to-die-for performance, but some of them are big bricks. In the future when I'm feeling flusher with spending money once again, I could see myself wanting to try the little 50/2
Voigtlander Apo-Lanthar. But for the past few months, my go-to lens has been Sony's 50/2.8 macro, more or less permanently set to f/6.3: It may not be quite up to the level of Sony's premium glass, but it's still pretty darned good.