This button-read system was used in the eighties in consumer electronics, and quickly abandoned.
I would love to imagine that happened - but it most certainly did not!
Very unreliable long term because of oxidising switch contacts.
Actually, moisture in the lubricant included in the switches is I believe the main problem. The resistance goes down, not up, eventually leading to a "cipher" - a switch that spontaneously actuates, or appears to.
The other symptom is "function migration" where the function of the buttons moves from one to the next!
I have a whole collection of devices that have failed through this process - because I tend to use them beyond their 18-month expected "Moore's Law" lifetime. Many MP3 players (suffer from being carried in a sweaty pocket), computer monitors, a GPS and an Android "tablet". The latter is illustrative - the On/Off switch simply refuses to work, first intermittently and now completely. More to the point (well, before the failure of the On/ Off button), first the Volume Down button would not work, then the Volume Up button became the Volume Down button.
An alternate failure mode of interest, demonstrated by disconnecting the switch chain, is that the ADC input of the main control chip itself develops leakage.
For this reason, I strenuously advise against this form of analog switch multiplexing. Whilst membrane switches are capable only of a few milliamps, I suspect it is important that they are subject to that milliamp or so in the act of switching. Of course if you propose to use properly made full-size switches, it may be a different matter.
They must have been using extremely unreliable switches in the eighties!
Most likely far better than those used now, sad to say!