I use a Canon 5D MKIII that I bought used in 2022 as my main professional camera. I may have bought it used 4 years ago, but it still feels like a new camera to me and I haven't lost any love for it in those 4 years. Before this camera, I had been using an original Canon 5D as my main professional camera, which I had purchased in 2012. I absolutely loved that camera as well, and I only upgraded to the MKIII because I thought it was having trouble communicating with my lens. It turns out the issue was the lens and not the camera, but I had already upgraded to the MKIII by the time I figured this out. I'm not mad about the upgrade though, as I absolutely love my MKIII. The only thing I really miss now about the Original 5D is the size of it's files. Those 12 megapixel files took up a lot less file space than the 21 megapixel files of the MKIII. Other than that, the photos render the same. The superior AF and low light capabilities of the MKIII make it much easier to realize my visions though. Now, my Original 5D sits on a display shelf with my OPPA trophies.
I do plan on upgrading again this year, but I'll be sticking with a DSLR. I plan to get a 5D MKIV because I would like to have two camera bodies for weddings. The MKIV will likely become my main camera and the MKIII will become my backup, but in the meantime I still find it to be a complete joy to use the MKIII.
The cost of L series EF mount lenses in the used market is a huge benefit as well. I bought my dream lens in 2024 (a used Canon EF 85mm f/1.2L II) for less than $800, which was an unheard of low price back when the EF mount was standard for Canon cameras. Next I plan on spending about $500 on a 35mm f/1.4L lens.