You are putting words into my mouth.

Let's try to be clear on what I said.

Canon and Nikon were the only two real top dogs and were comfortable not investing heavily into mirrorless at all and with them being set in their ways in other ways no reason to believe otherwise.

Sony comes and has been listening to the people and delivering in ways Canon and Nikon have not up until then and now is the trend setter if someone wants to be competitive.

It's not about the vertical grip. I'm rather impartial either way with only a preference to it being built in since I'll add one anyway. Not like I can feel the difference it's just authentic. It's about a truely consistent tool with consistent AF and all around performance. But R5 is far away from a 1Dx III outstandingly consistent and accurate AF and dependability. Not just in build but every aspect of it. It's just a professional tool meant to deliver. The other fancy features of eye detect while super amazing mean nothing when it can't focus on the bride and groom during the ceremony. That's a nightmare that almost happened to me and I switched to my 1Ds III for the shot. This is not acceptable to me and it has consistently plagued my experience with it and simply put others are willing to deal with it, but it's not pro level dependability. 80 or 90% doesn't cut it on someone's big day.

The fact Canon is doing well is besides the point. Canon has literally been pushed into being competitive. It's Sony who has done this because of the of all the things I have mentioned before.

The fact so many have switched is the reason they are having to adapt. When it comes to the R3, look at it from a person who is not heavily invested or in my case most of my gear stolen and only have a few things left.

There is nothing compelling about the R3 that makes me worth considering it. It's really performing plus or minus the same to the A1 and I loose half the resolution. Even if I didn't particularly need resolution it would behoove me to choose the higher resolution option if for no other reason I can view it on a 8k display and for future proofing as much possible.

Other option is wait for the R1, it likely will cost $8000. But I get to stay with a familiar brand and operation and lenses I really like. But if it's something like 30mp. I not sure I would stay with Canon.

This is just my scenario. So many simply sell and switch.

Ad far as seeing people switching over a lot it's not ancedotal. It is a trend. Even studies/stats are nothing more than asking a small percentage of people their viewpoints, sometimes only a couple hundred or less are what studies can be based off of. And they probably sre not that far off either because they are indicitive of something really happening.

Simply put, Sony revolutionized the camera industry in so many ways and now everyone is following suite. Those who don't will be left behind. Canon and Nikon probably best case scenario would hang onto the DSLR for a lot longer. They might have not ever fully switched to mirrorless and keep it as a second line of products.