Online games that aren't sold as services (like WoW with a subscription) wouldn't need to work online or with servers. The bare minimum this asks for is some state of playable which could include just the ability to run around on the map on a local machine... Ross Scott has talked about this a lot. We would love more, but we are asking for bare minimum.

I'm really skeptical of modern online infra. I've worked on two MMOs as a Tech Artist and the way artists, designers, etc worked on the game was with a local only build! One of these companies actually barred WAN access from our dev machines so LAN only also worked for internal playtests! Trends to make dev builds online only are quite awful for developers in the trenches and are more about exec control than any usefulness added by such requirements.

Complex server infrastructure that you mention is also not needed if you ask me, at least not to the point to make it too hard to widely ship. I'd be fine if someone still had to stand up a centralized matchmaking server still, just allow any player to do it.

As an example, compare Helldivers 2 and WoW. WoW is vastly more complex but Helldivers 2 uses more modern cloud "tech" that didn't exist 20 years ago. Both had issues keeping up with player demand on launch. So what's the point of this newfangled tech? Well, it's devs convincing players they're getting a better service or good (don't know which!) and that this complexity based lock in is worth it. And it's also cloud providers like AWS and Azure convincing devs to create architectures like this which lock devs into these platform holders. I'm not convinced were seeing real improvements on the dev or player side... Scamming turtles all the way down if you ask me.

It also turns out a lot of this stuff is able to reverse engineered. I'm right now playing original Demons Souls with full multiplayer connectivity (including matchmaking from a central private server) which required PSN support of the PS3 days. WoW private servers also required a great deal of reverse engineering. If online randos can do it...

Plus WoW private servers literally revealed a new revenue stream to Blizzard in the form of WoW classic:
"After a month or so of large scale protests, Blizzard invited the Nostalrius team to the Blizzard HQ to present the case for Vanilla. An eighty-page "post-mortem" document describing the development of Nostalrius, the problems that happened and some marketing strategies was presented to Blizzard, and after some time, released on the Nostalrius forums"
https://en.wikipedia.org/wiki/World_of_Warcraft_Classic

Others have also mentioned middleware licenses as a problem. Those licenses would adapt just fine. A single game will ship with multiple binaries of RAD Tools, Havok, SpeedTree, etc. So now a player has potentially hundreds of copies of different versions of all these binaries and libraries. This is a completely solvable problem that won't stifle development or even require leaking of trade "secrets".

Also, this is relatively new problem in the industry. The market grew just fine allowing for players to use their goods more freely. That any such regulation would hurt the industry is dubious at best, corporate speak at worst. In fact, I'd argue that enabling player freedom an creativity over their purchased goods has helped the industry grow to where it is today! Counter Strike was a mod, TF2 was a mod, PUBG was a mod (Fortnite wouldn't exist with out it), DOTA was a mod! Minecraft in part exploded cause of mods. A healthy and innovative free market demands player and user freedom!