I've been told that .htaccess should be avoided when possible, as it reduces the server performance and new servers disables it or just don't implement it anymore.
The part about compatibility is absolutely not true; the part about performance is kinda true but probably irrelevant for you.
What the person you quote was probably talking about is that it's faster to put Apache rules into the central configuration instead of .htaccess files: The former are loaded once into the Apache process, and don't have to be looked up on every request.
However, this is not possible on shared hosting - using .htaccess files is the only option you have there.
If you have the opportunity to put configuration options into the central configuration (i.e. you have admin access to the server), and you're worried about performance, do it. But chances are this is a non-issue really. There are lots of things to optimize in a web application before it is worth looking at this.
For simple rewriting tasks on a low- to normal-traffic web site, .htaccess is still the way to go.