Kind of. I haven’t paid attention to the meta for a long time but you do have to reach certain mastery ranks to be able equip (some of) the more meta weapons. But the requirements aren’t usually that high. E.g. the Fulmin is MR 8 and the Arca Plasmor is 10. The Xoris is only 4. So yeah you have to grind equipment to get MR ranks to be able to use some of the stuff you want but eventually that’s no longer an issue and you can use whatever you want. If you have a setup already that you think can clear the Star Chart (non-Steel Path) that’s still a crap-ton of content to play through. You don’t need to keep doing the grind unless you want to do the harder content.
It is a looter shooter, though — the grind is the long-term point — there’s always some new stuff to collect, currencies and reputation to earn, etc.