Not sure what precisely you expect to need on a tablet simultaneously.
For instance, if I were to install War in the East on it, I dare say it is unlikely I give a hoot what else might be on it
My tablet though holds 64 gigs of data. For point of reference, my entire wargames collection sits in a folder that is just shy of 52 gigs of data as installer files. That's 38 folders of wargames where in some cases a folder is my entire Matrix Games Close Combat Series or my entire Panzer Corps series or my entire Battle Academy series. I also have both WitP and WitE along with it's expansions in their folder. I even have that bloated data pig Legends of War present with its 3.7 gigs of data. I have almost the entire Panzer Campaigns and the entire Squad Battles series.
Now if a tablet can hold dang near all of that, I think needing more must mean some of your games are just over inflated garbage.
My tablet currently has Battle Academy series, Panzer Corps series, Conflict of Heroes series, and TOAW III on it. I currently don't have anything else installed on the laptop either. Because it is easy to buy a game, but not so easy to find the time to play it sometimes

Plus, ME I am not inclined to consider some games as light entertainment while out and about

I can't picture getting in a few minutes of WitE to tell ya the truth. Sometimes it doesn't even matter if something can run something, if it is unlikely to ever be desired to be present.
As for useless junk paperweight desktops. Well ya, I suppose a piece of scrap waiting to happen garbage running some has been OS from 10 years ago might be all a person has to work with. I've found though, that the reason desktops have any value at all, is because you can easily swap out the old parts. If your rig actually DOES have 10 year old parts in it, you ARE definitely poor. Because even my rig which is worth so I am told about 50 bucks, still has parts that are less than 5 years old in it.
There's nothing magical though about half or more of the games catalogue here. There mainly games from the 90s with a facelift or two. Or they were never graphically demanding to begin with. That an old desktop can run them is no accomplishment

Anything can run them for the most part. It's a very rare wargame that demands cutting edge hardware.
Tablets are only different from desktops in one category, size. That and the screen is part of the device.
But I've seen computers built into televisions too. And with touch technology becoming the norm they are essentially just massive tablets too.
Once the technology gets away from the need to constantly swap in and out parts, the desktop will have come to an end to it's utility.
I for one, don't expect a device to need to perform longer than 5 years.
If it actually continues to run after 5 years, fine.
Chances are though, that something sufficiently innovative will as always render the old no longer of interest.
I am not in the market for a new desktop mainly as they offer nothing of worth I can't get elsewhere. If I actually need a new rig, I will just buy a new laptop. The parts in the one I have though, they have already exceeded the usual needs. I don't need TB of data storage. I don't have TB of data to store. I currently have the entire Cosmos series as emulated disks, and the entire World at War series as emulated disks on my laptop just on the chance I might need to go somewhere for a few days or whatever, and it gives me something to watch. I don't even miss the data space. You should see the size of my pdf library on my laptop. I have all my music on it.
Our capacity to make storage devices has exceeded our capacity to acquire data to some extent.
Oh and your new parts every 2 years, costs no less than our entirely new devices eh

Wargame, 05% of the time.
Play with Barbies 05% of the time.
Play with Legos 10% of the time.
Build models 20% of the time
Shopping 60% of the time.
Exlains why I buy em more than I play em.