The OG Halloween adjusts to $181.4M. Yeah, nothing amazing, but the first movie had a limited advertising campaign, and managed to gain more popularity through word-of-mouth, TV airings, VHS, etc. Again, just about everyone has seen the movie at least once
And when it comes to H20, it was a totally different market. Not just because of horror not being as big as it is now, but also because of the hunger for nostalgia. Look at the top 10 for 1998, and the closest example to a movie that got help from "nostalgia" is Doctor Dolittle, and even that's a stretch, and I guess Godzilla?
Now look at the top 10 for 2018. Even stuff like Black Panther and Ant-Man and the Wasp kinda fit the bill since the MCU's over 10 years old. Even Aquaman got a boost from being a legacy character whose been in a bunch of cartoons. Deadpool's the only one that was definitely not nostalgia-driven. It's a very different market from 20 years ago.
And yeah, I think a new Friday the 13th movie can open to 60M easily . The '09 remake opened to over $40M at a time when horror wasn't as big as it is now. With Halloween approaching $75M, why not a character just as popular?