So LOTS and LOTS of people are switching to Sony because they are just so competitive and if you are not brand loyal it makes a lot of sense for a lot of people.
I read similar statements frequently on forums, and people have been making similar claims for years. When I ask for evidence to support the assertion of this mass migration, the usual response is along the lines of, ‘I know like four people who switched’. Can you do better, as in provide actual data? Not trying to be argumentative, just asking you to support your assertion.

For reference, the most recent publicly available data are from 2020. Canon gained ~4% market share for interchangeable lens cameras and had about 50% of the market. Sony gained 2.5% market share and had close to 25% of the market. Nikon lost ~6.5% market share and had just over 13% of the market. So the data suggest people are switching from Nikon to Sony, and even more people are switching from Nikon to Canon. I really don’t think competition between $5-6K cameras are going to affect the market as a whole.

One other consideration is that even if the R3 appeals mainly to Canon users, that’s half of the entire ILC market.

Nothing is stopping you from switching, but I don’t think it’s reasonable to assume that your views, whatever they are, represent those of a substantial number of others, unless you have actual evidence to support that assumption. Unless you have data more recent that last year’s published market data, or data from a reliable source on a subsegment of the market (such data are hard if not impossible to find, since manufacturers don’t provide granular data), making sweeping statements about what LOTS of people are doing may not be the best choice.