With most places outside mid-sized or larger towns having a few Mbit/s connections at best, and games size in the order of tens GB, and the situation likely to improve minimally even as town dwellers get hundred Mbit/s connections, a new console without physical supports for games would be horribly uncomfortable for a too large share of potential buyers. It's also true that optical discs, while cheap, ar also slow for level loading when playing, so optical discs with HDD or faster storage to ionstall games on from disc or digital connection is still the best solution.
Faster than HDD mass storage solution will be adopted as they become cheaper and viable, in a totally smooth way, right now users can already replace HDDs with SSDs quite easily, but currently a large sized SSD would drive console price excessively up, so HDDs arfe still the standard equipment, but in future the transition will be easy.

About optical drives, nobody prevents console producers from making also cheaper SKUs without them for buyers that have good connections and are fine with going full dd.
Once it's established that a game needs anyway to be installed on HDD or faster, physical supports and digital download can coexist without any problem.

About solid state drives faster and more reliable than SSDs, they're obviously welcome, but while using them as aftermarket replacements can be done as soon as they are supported by console, the right price for the right size must come before they can become standard equipment. Exactly like it happens to SSDs.

I know I wouldn't miss them myself. But I know there's people who want the physical media for a variety of reasons, so I don't think they should cut the cord just yet. Maybe when everyone has satisfactory and competitive internet speeds and data as a standard. But until then, they should stay.

People need to stop cheering for cartridges, we dont need games to be even more expensive than they are now. A problem the Switch is already starting to have with bigger games.
I would always like a machine that can play games and movies, come as an all in 1 package......dont want an all digital future unless i can actually buy something physical

I still watch some Blu-rays and a few DVDs, so I need a DVD/BD driver and I like the fact that PS4 has it. I'm far from giving up my DVDs and Blu-rays and I don't want to have a BD player.

Agreed. I see no reason whatsoever to go back to carts. Unless it's a tablet console like NSW.

Sort-of correct.

The Xbox One will install *all* of it's data to the Hard Drive before you are allowed to play it. (Some exceptions like: Halo: The Master Chief Collection, which installs a game at a time, so you can play Halo 1 while Halo 2 is installing.)
From there the Xbox One will stream data from the technically superior mechanical drive (Verses Optical) to system memory.

The Playstation 4 however... Will let you play a game sooner after an initial small install and continuously stream data to the mechanical disk which in turn streams to system memory.

There are advantages to both approaches. Sony lets you game faster, Microsoft's approach should provide more performance, especially during random reads.

Last gen did take it to the extreme, it was because developers were trying to free up more memory, the less information you need in memory and the more you can stream on-demand, the better.
There were a few games that would stream from both Optical Disk and Hard Drive on the 360 though.

We probably won't see a return of that this generation, there is less of a need.

But if the consoles were cart based, they would side-step the entire install procedure and just stream directly from cart, carts can easily be faster than a HDD. It will be more plug-and-play experience if you will.

Carts tend to be faster than mechanical and optical disks.
Carts tend to be more durable than optical disks.
Carts tend to be smaller and more portable than optical and mechanical disks.
Carts use less power than optical and mechanical disks.

I do agree that there is zero sense to have both carts and an internal SSD though in a fixed home console. But if you go the SSD route and only have like 32GB of the stuff, then Carts would still have a place... I don't know about you, but I am sick and tired of waiting for hours for crap to install on the Xbox One.

I don't care if it's a disc, as long as I have a physical media option.