My parents are older and have a large home and are not at all tech savvy, but they realize that they need more Wifi range because their one existing router isn't good enough. However some of the good mesh routers can be a pain to manage, which ones can be easily "set and forget"?
My eero setup have been running strong without any intervention for a couple years now, across a couple different houses and isps. It’s been a great investment so far.
The Google Mesh (Nest Wifi) is easy to set up and requires no ongoing admin. It just auto updates in the background.
On the downside it's not very configurable, like you can't even have separate 2.4 Ghz and 5 Ghz SSIDs.
But your parents probably won't care about that. Just get a three pack, set it up in 10 min, and you probably don't have to worry about it again (until Google abandons that product line like every other).