Yep, you got it!

There indeed are older kinds of weapon tech, ... but yeah, they havent't been widely used for like... thousands, tens of thousands of years before the Battle of Yavin 4.

It does indeed end up being a sort of... largely post technological progress setting, most things are ossified... almost everytime something is doing something 'novel' with tech... its basically been done before, or its just outright a 'find the lost relic' scenario, and yeah, you do run into weird situations where 'ancient relics' can actually be quite useful in more or less rare and specific scenarios.

Hell, you can even say that... the Force itself is roughly analagous to the Warp, in many ways.