Interestingly enough I just played it for the first time earlier this year, which is weird that I didn't earlier since the first one is one of the most iconic horror games and it definitely felt different. First one is better but I really dig what they tried to do with the second since it's so much different than a most of other horror games, especially with themes.
But tbh I didn't see similarities with RE as the whole point of Outlast is that the player specifically can't fight back and blow stuff up and has to run and hide This is because the player in both games is an average journalist who only has night vision camera to navigate, not a cop, special forces operative, boulder puncher, matrix, badass spy etc.
Though I did see the similarities with RE Village and even though that's one of my favorite games, they really blew it by having a similar story to Outlast 2 and not having the entire game take place in the Castle and Village with only vampires and werewolves.