Today, in 2025, neither are safe assumptions to make. Much in line with the Internet meme's of "new college freshmen in 2025 have never known a world without cell phones" and the like, in 2025 there is now some rather large subset of the computer using population who have never known of nor used a "multi-user computer" and have only ever seen and used "single user computers" (even if the OS on their computer is inherently multi-user, the overall 'computer' is 'single-user' from their viewpoint).

And, if they have never seen nor used "multi-user computers" they also have not encountered "runaway log growth" or the like -- or if they did it was from their own process that they immediately killed, not by some other user on the same computer filling /var/log/ in the background.