When possible, try to prefer DRM-free versions of games. If there's DRM, then one doesn't really own it. PCGamingWiki [1] is a great resource that will list the DRM status of a given game for different distributors (yes, some stores may have DRM while others do not). In general, GOG [2] is all DRM-free games.
You still need to download it. There are plenty of situations in which you might not have downloaded it yet or might have lost/deleted your copy, knowing you can download it again.
Also, I think the DRM people are referring to here is the kind that consists of rootkits, monitoring software and similar or, in simple cases, refuses to run or gives you some kind of penalty when it detects certain other software.
Imagine if someone bought something for pickup from a store, never picked it up, and the store went out of business and liquidated. Did they ever really own it? I don’t know.
I don’t expect any guarantees from digital goods being stored for free in a digital warehouse, unfortunately many do. One doesn’t own the nebulous copy on the distributor’s server, they own whatever copies they downloaded.
Sure, just like the olden days. But you still need a license key or equivalent - for an offline check. And in the case of an app store that is handled by the app store, you never get or see the key. So if you are banned that doesn't help.
And even if you had a key you still don't have access to the install media. You could try to extract it from your drive but there is no guarantee that will work on another computer or OS-install since the installer might optionally install what is needed on that computer.
This at most technically right and definitely wrong in practice. I am unsure if there is an existing exact definition of DRM (free) or you're using an uncommon definition of "license" but in practice services like GoG advertising DRM free and people buying DRM free all mean that there is no licensing check whatsoever.
A GoG game comes with a single installer executable (single as in it is the same for everyone, no built in license) that and the resulting game it installs can be freely copied and used on as many machines as you like without any requirements. For example you do not need to have an internet connection or be running the GoG store application.
So if you have downloaded and backed up the installer of the game you bought on GoG then for all intents and purposes you own this game. It does not matter what GoG does from this point on. You will always be able to use it.
I will concede that the meaning might has changed with time. But at a point DRM was synonymous with online-checks and/or invasive spying and infecting the operating system. And that holds in spirit in today given all the criticism about DRM. It has never been about the inconvenience of entering a serial number (even though that indeed is a bit inconvenient it is most certainly not the source of the (justified) DRM hate we have today).
The license key you entered and the following offline check when installing from CD/disk was/is considered something entirely different.
I'd argue that the only reason that games today skip the license-check has absolutely nothing to do with DRM but with it being out of fashion and not considered to fulfilling its purpose anymore.
The one exception to this is that a key for multiplayer access in mostly single player games is sometimes not included in the DRM definition. GOG has a number of games with codes needed for online access via central server; this is needed to be able to ban players for abuse and is still technically DRM but I personally consider it different type of thing when the game is primarily offline. Best is when there are multiplayer alternatives to the central server that don't require a key but that is fairly rare. Personally I don't use multiplayer anyway.
All in all, the experience from GOG is much more customer friendly than other game stores (there are only a few other tiny stores that I know about that are DRM-free and don't require their client to be able to buy and/or download games). They aren't perfect but you can download the installer directly from the website if you want or use a client if you want. Games work fully offline with no code needed. You can refund a game for essentially any reason within 30 days even if you have downloaded and played the game (there is some unspecified limit to number of refunds but it isn't tiny if you are just refunding a few you don't like). I'm not 100% certain but I'm fairly sure they don't ever remove inactive accounts.
Unfortunately, the value of DRM-free is often reduced somewhat by the "release a buggy mess and if it sells well enough fix it eventually" philosophy that most developers have these days. Not having access to updates can worst case make the game unplayable and often makes it less pleasant (of course, there are also cases where updates make it worse :/). So DRM-free isn't a complete solution for not being able to access an account, but at least once you have played a game you can play the same version again even if you can't access your account.
DRM-free games generally do not have any license key (I’ve never seen one with it, but that’s anecdotal).
I’m not sure if an offline-only key check would be considered DRM; maybe is. Realistically such a check doesn’t do much, so what’s the point in including it. Back in the day it was often required to have one of the discs inserted to play—that is definitely DRM.
[1]: https://www.pcgamingwiki.com [2]: https://www.gog.com