There were instances where Switch Has Authority wasn’t available and had do make some changes to get the same effect, meaning be sure it ran on server only. I really thought that Switch Has Authority meant that true server, false client, as that is what I saw in a video or some post, can’t remember, it was a long time ago, and since then I used it with that in mind…
Now Is Server is a lot better, as that is available in those situations were Switch Has Authority isn’t and makes those situations (in my case) a lot easier, I can simplify the code/nodes.
Maybe the node Is Server wasn’t available then (it’s been like 3 years since I started playing with UE, and 1.5 since I actually started working on my game, a new fresh project), or maybe the one that posted didn’t knew that well what they were talking about?! I really don’t know. But if I’m to believe Gemini/ChatGPT that node was added in 2016/2017, so it might just be the latter.
So yeah, thanks for that observation, it will really be useful! 
Don’t worry, I understood you, and I do have some situations where I have variables for replication were users can connect later (like lobby elements for example). I only wanted to explain that in my case, inside the maps that players actually have the action and dynamic elements (and everything truly matters), that is not an issue.
Yeah, from a professional standpoint I should do it right, but I’m the sole developer of the game, so some elements are going to be more “relaxed”. 