Earlier quoted context omitted.
Internet connections cost poor people nothing in 1970 because they weren't necessary and could happily live their lives without one. The real item we're looking at here is *communication*, which was cheap: the stamp you needed to send in the form for your taxes cost a few cents. You could get away with using payphones for the few phone calls you absolutely needed to make. In 2021, internet connections and cellphones…
An internet connected smartphone is not equivalent to the postal service (plus a pay phone or landline I guess). It may be that you use a computer or something else for the things that most people use smartphones for, wand so don’t realise how much they cover. You also didn’t mention having to go to the library (distance + fuel/car/travel costs + more time) for information, finding jobs from newspaper advertisements…
In 1970, obviously nobody expected you to own a smartphone because it didn't exist. Noone had access to such a thing. Not so in 2021 western Europe. The example very much holds in that sense. You could fully participate in society without that expense.
I'm not speaking of keeping up with the Joneses here. I'm speaking of pervasive implicitly embedded demands on people's lifestyles.
What do you think about the effects of the way housing insulation requirements are often written?
What do you think happens when you invite someone to a party at your place in the countryside that is only reasonably reachable by car?
One of the best ways to get a feel for this kind of thing is to go live in an area with significantly lower median purchasing power for some time, a place where the average trustworthy hard-working person has difficulties making ends meet. I've done so. Even if I lived a lifestyle of relative luxury myself, it helped widen my perspective. I can absolutely recommend the experience!