Unlikely. While many of us, including myself, have been happy to reduce our use of electricity in many ways - communication is not one of them. Smartphones and technologies actually use very little energy compared to most other domestic electric devices.
What green-minded people want (we are all ages, not just Millenials and Z's) is an immediate* transition to renewable energy power sources, ie, solar, wind, hydro and solar thermal. (*over the next 12 years, starting today) It includes the use of massive batteries like the kind Elong Musk built for South Australia, to assist with times when sun or wind is temporarily insufficient. It includes larger supply lines to carry power from one geographic region to another. Solar thermal would be the main driver for industry and applications requiring last amounts of power. There are an enormous range of strategies and technologies which will need to be applied to bring greenhouse gas emissions back to pre-industrial levels. These methods are well known and proven. If put into action they will cost far less than the price we will inevitably and soon pay for global warming.
There will naturally be problems - as there always is when there are major changes in industry-wide work practices. While there will be fewer jobs in oil and coal, there will be more in building and maintaining renewable energy infrastructure - enough to mean no net loss of jobs. Governments and bosses will need to assist in helping ease that transition, especially with re-training and in some cases re-location. Big business - the likes of BP, Shell etc - have been collecting the patents on many designs for the best in renewable power for over fifty years. They've been anticipating the day when the need for change becomes critical, and expecting to control the transition. They will be the least likely to suffer any loss of profits. Yet they will delay as long as law allows in order to milk profits from fossil fuels while they still can.
The planet can no longer afford to wait. The crisis is already upon us in many parts of the world.
It depends. If it is cool to do it, they will. It is all about being cool. Right now saving the planet is cool and shows you are aware and care about the right things, so they may fall in line with that.
An individual portable telephone uses very little electricity, but one of the world's largest, if not the largest, electricity user overall is the Internet and general telecomms network, primarily in the massive exchanges and servers its needs.
I've heard one estimate that if you translate this to energy use generally, it exceeds that of the word's airlines.
However, it is wrong to focus just on the electricity involved.
A portable 'phone, like many modern electronic devices, contains a quantity of various metals including gold and rare-earth elements, and huge numbers of these devices are discarded after only a couple of years' or so use, still serviceable, without thought of salvaging their materials. Or indeed, refurbishing the instruments intact for continued use.
(It was to address such waste, as well as rather exaggerated fears of the more toxic material's possible effects, that led to the EU's Waste Electrical and Electronic Equipment Directive ("WEEE") Directive. It strives as far as practicable to enforce recovering all such scrap for its materials. That is feasible for commercial, State and local-government concerns; but cannot stop ignorant households merely throwing small items like 'phones, chargers, electronic toys and dry-cells, into the ordinary land-fill waste-bin.)
