After you have understood an algorithm and can write it on your own, then you can use snippets. But, as a newbie you would only use DFS, BFS, Binary search. So there is no use of snippets for beginners.

I think from my experience writing code with/or without macros makes little or no difference in speed, hence I write without any macros but I do use snippets (for things like Modint and Segment Tree) which I found very useful.

I use snippets only for things which are difficult to write and debug fast. Like segment tree, sparse table, lichao tree etc.

But i feel that if i use snippets i forget how to write things by my own. So i try not to use them if i can. Starting from an empty program is a good practice also.