Don't. Don't. Don't believe the hype. (Megapixels aren't everything)
I've been considering a return to full frame photography for while now since Canon finally released some professional level mirrorless cameras. I was a Canon shooter my whole life until I got tired of hauling round heavier gear through Sri Lanka, envious of the Fuji X series cameras a few acquaintances had shown off to me, ander after picking up an X Pro I was sold.
My bread and butter as a professional photographer is studio portrait and headshots, so sensor size honestly does not matter to me, and it's nice to handhold a lighter camera for a few hours during a shoot than a mirrored camera with heaver glass. However I do love travel, landscapes and astro which is where a full frame is a bit more desirable on a personal level. I've started to look at the two latest Canon offerings, mainly because I know Canon, I trust their quality and despite a few years since I've picked one up I'd still be familiar with the controls.
So I started checking out some reviews of the R6, a 20MP full frame offering with dual card slots. The dual card slots are important if you shoot an event, a wedding or out in the wilds to ensure you have a backup if anything goes wrong. In a studio setting, it's not so important as you'll likely be shooting tethered to a laptop and getting a second copy on your hard drive. I was surprised when reviewers (who claim to be professionals) are picking on the 20MP sensor, calling it an enthusiasts camera and in one case a youtubers camera. They seem to have forgotten the flagship £6,000+ camera by canon has exactly the same sensor. This is a camera that retails at £2400 for the body alone which I would say is out of reach for a student or a lot of enthusiasts.
Yes more megapixels can let you print bigger, but guess what? The bigger you print, the further you need to stand from the photo to take it in. So even if you print a 20MP image large and there may be some grain if you stick your nose against it, nobody on earth is actually going to do that (aside from one of these YouTube nerds).
What I will likely do is keep an eye on the pricing and wait for a deal with a suitable lens such as the 24-105 f4.