I have zero loyalty towards either brand. I'm looking to upgrade from a fixed-lens Panasonic FZ1000, and a7 III and Canon R6 are the primary contenders. Main purpose is travel photography, I don't care about videos at all.
Before Canon appeared in the picture I was planning to buy a7 III with Sigma 24-70mm f/2.8 for about $3k total. It looks like similar set of R6 + Canon RF 24-70MM F2.8L lens will be about $4,7k - over a 50% premium, with not much to justify it at least in terms of specs for my use case. At below $2k with attractively priced option for 24-105 f/4 kit lens it could be worth considering, but at $2,5k body-only + more expensive lenses, it would have to crush Sony in terms of image quality.
Just looking at just the specs sheet and prices (especially for an aftermarket lens) is the wrong way to look at it. If you want cheaper lenses, the Sony has them covered better (but not everything is expensive with Canon, EF can be adapted). It is also smaller.
There are advantages and disadvantages to each system, one thing is just to put the camera in your hand. The Sony is smaller but the grip isn't very comfortable, it is not really made with a 24-70 2.8 in mind.
The Canon sizing (imho) is just perfect.
They also operate in a different manner.
A much older camera with loads of stock available everywhere is going to be priced lower than a brand new one with features we haven't seen in this category, there isn't going to be any surprise about that.
But there are some compromises with that, which you will find once you start using them. Or you don't, that's fine too.
Just don't think that the R6 needs to "crush" Sony in terms of image quality, it probably won't (apart from the colour which Sony users are sensitive about), because its advantages are not related specifically towards that, it is more about the AF system, the wider mount, handling, higher-end lens selection, etc, etc. it's about everything that may attribute to what can make a camera "great" overall.
For travel purposes, the EOS R or even an EOS RP should be taken into consideration, for travel they may not be that much weaker than the R6 in practise, and they cost way less money. There is also the Nikon Z6, etc. plenty of options to choose from.