The templates comes by default with Niagara.
You can choose not to use it if you don’t want to. (When you know how each module works).
Blueprints works exactly the same as C++ (blueprint is a class). Blueprint has advantages and disadvantages over C++ code.
I think the advantages make it worth using.
If you don’t like it you can always automatically convert it to C++.
By the way, I’ve been watching the first video you shared for a while and the first thing the man added was a template XD. Do not worry about it. After doing a few tutorials like this you won’t need templates.
Cheers!!