Is your point that developers today aren't as good/benevolent/whatever as devs back in the day? I'm saying (sarcastically, I suppose) that the same type of developers exist today. What does survivor's bias have to do with it? Is my point moot because GMOD exists?
Your point is moot because there is an unending hose of indie games being created and knowing that 2 gems exist doesn't mean the rest of the cottage industry measures up to the things being achieved earlier, and nor does said indie scene have a similar rate of success as the old industry back then.
Tbf, games were easier to create using in-game functions and logic that was created for another game. Modding a whole rework was easier than making the entire game from scratch. Undeniably lethal company is similar in look and feel but it has better game play than some mods.