Who are these people which require 5 handsets?

I have this exact Panasonic phone set... and have not been pleased with performance. Despite having the home base centrally located, the remote photes located farthest from the base unit have poor to non-existent performance.

Our home is large...but not that large, with the maximum distance from base to a remote being less than 85 feet. Maybe if your home is much smaller these things would work, but don't bank on it!

Lots of handsets are handy to have, one per room till you run out. DECT6 sets usually have an intercom feature too, nice to have portable instead of wired to a wall.

Most people feel these have pretty good range. Note the 5/5 eggs from reviewers. I have to suspect #2 has something else interfering in the 1.9GHz band, usually you can take a phone like this a block away outside and it'll still have good signal to the base inside, unless there is other RF interference, though you'll want to keep the base away from any large metal objects which can block a significant % of signal.

... or I suppose it wouldn't be impossible for a defective unit to pop up here and there.

I have the 4 handset version and I love it. I can take mine out to my mailbox(75 yards) without losing the connection.

It's really convenient to have a phone by my bedside so I don't have to get up and go to the living room to answer.

You can set it up to not ring after a certain time.

#1 I don't know where you live but they tend to put a phone outlet in every room here standard. With cordless if you have kids you can bet the phone won't be anywhere near the charger. Does make for a good workout racing around the house trying to find the ringing phones. Kinda like an Easter egg hunt. More phones cut down on this.