1. Just have to say there was only one successful home console in Generation 7, the Wii. Sony and Microsoft both posted huge losses from their gaming divisions throughout the generation while Nintendo posted record profits. Only Nintendo's system was successful and it wasn't even close (not in profits, which is the only metric that matters for a company's success).
2. The console market is definitely not stabliizing. It is transforming quite a bit. Nintendo and Sony are the only true competitors left in the traditional sense, and Nintendo is about to clobber Sony. Microsoft and Google are playing a different game. They are both trying to become the "Netflix of gaming" and they want to get their subscription services on as many platforms as possible, which might even include Switch and PS5 if they are allowed. The Series X really doesn't even matter anymore. It is a token piece of hardware. Microsoft's real focus is on Gamepass/xCloud at this point.
So there are two battles that are about to happen: Nintendo vs. Sony and Microsoft vs. Google. But Microsoft and Google are going to try their best to get on every piece of hardware they can including Switch and PS5. The console market is changing a lot.