I went through my digital library and it was a little hard to say which games are also available physically so the numbers might be a little off.
Furthermore I have to add that I sold a few physical games when they either became part of Games with Gold or I replaced them with a digital version when they were for sub €5 in a sale.
On top of that, I accumulated tons of MS reward points over the last 12 months and just recently cashed them in for digital games. Using this "money" I bought 7 digital games (over 10% of my digital library).

Physical X1 games: 82
Digital X1 games: 61
Total: 143
57% physical

There is also the chance that some smaller title initially released only digital get a physical print later on.

I buy mostly physical if possible, but I am not stubborn and get it digital if it is a lot cheaper, convenient or other advantages. I am also much more inclined to get digital, with no DRM, like with GOG. But with DRM in place, physical games is often the better choice.

For the bonus question: I consider the Xbox Series S as a pure Gamepass-machine. I think Gamepass is a big value, Series S might be a cheap way into that. But maybe I decide not to get Gamepass at all or getting a series X instead to also buy certain games (then as physical if possible).

BTW: I have a graphically weak Linux-PC mostly for programming and web (VGC), that is why Gamepass on PC is no option for me.

If a game has a physical version, I will never buy the digital version. Digital-only is also more likely to make me skip a game altogether.

0 % in XBOX. I have 150 digital games in this console.
100 % in Nintendo Swicht.
I m going to buy a Xbox Series S because i have a Fat Xbox one, so this will be a good upgrade for the next 2 years.

0% Physical.

The last game I bought on disc or cartridge was BotW in March 2017.

Bonus: I‘ll get the XSX for the power, not for the drive (I don‘t watch DVDs or BluRays on game consoles, they consume way too much compared to a BR player). I would buy the XSS if it was as powerful as the XSX.

Bonus bonus: Next gen will be "all-digital or bust" for everyone. Sony is preparing their fanbase already with the PS5 (the all-digital SKU is slightly less ugly).

I buy physical whenever possible, except for Destiny, because I play that game over the course of years. That means there's not much resale value, and I want the convenience of not having to swap out the disk. I think I bought one other game digital at some point, but I can't remember what it was.

As for buying a digital only console... I haven't done so yet. However, I think there's a good chance that I'll get a Series S at some point to put on a secondary TV, as a supplement to my Series X that will be in my primary gaming space. With Gamepass, and my Destiny playing, a digital XB may make sense for me.

I am planning to start this gen with XB, and will add a PS5 in some time later. Depending on the pricing of the SKUs at the time I decide to buy it, there's a chance that I'll go for the digital-only option. Presumably, this will be a machine for playing Sony exclusives (if it pans out that XBSX is the generally technically superior machine, that'll be my multiplat console). In this case, saving $100 on the front end may be worth it, if I'm only going to buy 10-12 games over the life of the machine. Also, at that point, a couple years into the generation, the early exclusives will be cheap to purchase digitally during sales. So, that eliminates some of the incentive to buy physical.

If I had a choice I would only e er consider a discless version of a console. The sooner physical media dies, the better.

80-99 % physical.
The only time I buy digital games are Humble Bundles and it's often only a few of those games that have physical counterparts on PC. Also haven't bought one in quite a while.