Mesh network versus a simple Wi-Fi extender

You almost never move your streamer through your home while playing music, so I don't think switching would be a real problem.  I do believe in keeping things simple though.  Mesh is great for large homes with lots of square feet to cover, including when you are looking for coverage say at the pool and the garage, that sort of thing.

Read the reviews on any extenders carefully too though, as I've had really mixed experiences far worse than audio quality.

You are doing yourself a disservice if you don't find a way to go hardwired to your streamer.  

Me and my neighbor both have ~2500 square feet homes.  We both tried extenders.  He was not  having problems with audio but his PCs dropping off.  I was having audio drop outs.   Both our experiences with extenders sucked.  He went to a mesh network and solved his PC dropouts. I followed suit.   My audio now is for the most part solid 😎.  Having a mesh node sitting near my main rig and hard wiring my streaming server to that solved my stability problems and I did not experience any degradation in SQ.   Note:  My HT, and about half the other devices in the house are hard wired to the base node or the router/modem.  

The mesh pods work much better in our house than the old extenders, which were really hit and miss.  So many drop outs.

Big fan of a mesh system.

I have a main audio system server/streamer hardwired to the base router unit and a streamer endpoint for a second garage/outdoor system hardwired to a mesh node in the garage.  I have not experienced any dropouts or other problems and the three nodes allow me to control either system from my iPad/iPhone anywhere in the house or outdoors.