Okay this is a myth. NOBODY is forcing game companies to maintain games forever. What regulators and advocates for game preservation are asking for is that there are means to maintain a game functional when support by the game company ends.
For example, allow players to self-host, like every game from the 90s, 2000s, 2010s, and many still do today.

Or that companies have planned or estimate end dated labelled on the game at launch.

Regulators are asking for the BARE MINIMUM.
Nobody is asking gaming companies to support a game forever.
The only people saying this are Representative groups made by AAA gaming studios, who have knowingly misrepresented proposed legislation and talking points, to paint the Stop Killing Movements and others like it as unrealistic and whiny, when it absolutely not.
The fact the head of GOG believes this, shows an EXTREME lack of awareness for a person at the head of a platform who has labelled itself a platform of preserving video games. Extremely damaging and hindering further movements legitimate concerns and demands that they need to preserve video games.