Should I get a third party router? Any other benefits of a third party router?

I am on Vodafone's 500mbps (openreach) service using their old THG3000 router not their new pro router.

I am getting 200mbps minimum in any area of the house, however I almost never get the maximum unless I am right next to the router.

I don't really notice the speed unless I am downloading a game update or big file (which is getting more frequent), which I then move my laptop and wire it into my router.

Tbh it would be nice to have 500mbps all around the house, which I think wouldn't be impossible with a good router as I already get 4-5 bars of signal strength throughout the home.

Are there any other advantages of a third party router? Is it worth buying one for the convenience of max speed around the home?