A new approach is to have multiple router kits designed to extend the main router's signal. The upside is that the above security and speed issues appear to have been addressed; the downside is cost.
I bought the Netgear Orbi from Amazon ($244 on Prime Day) but haven’t tried it yet- still sealed in box because I thought I might send it back. I’ve currently got a Netgear Nighthawk AC 1900 so not sure if it would be an upgrade. I’m going to try moving my router and possibly an extender— cheaper options if they work.