Before Jio, telecoms felt free to rip customers off on anything and everything. Charges for caller tunes the customer didn't set or ask for. Unknown charges in bills galore. Large areas in metro cities without coverage. Customer service agents who refused to help, and in many cases, tried to gaslight the customer. Trying to stop the service and move somewhere else was almost impossible, they tried every sneaky trick in the book to get you to stay and keep paying absurd amounts of money for very little service.
Jio changed all that; most of the bad ones either dropped dead or merged, primarily because they couldn't deal with an operator which was, aside from the clearly aggressive business practices, actually competent, plus priced itself aggressively and actually gave customers a lot, and handled customer service more effectively than the rest. Airtel upped its game and survived, Vodafone-Idea is on life support, and the rest are dead.
Now it's a different problem altogether - cheap data and free calls led to unabashed spread of spam and scam calls. Until very recently when TRAI actually started threatening telecom providers, it was almost transparent that the latter were just allowing large-scale spam and scam perpetrators to thrive. Then upper government levels noticed the fiascos during COVID after a few very public and egregious cases, and proper action started happening. This has led to more awareness and fewer unsolicited communication, and a surge of complaints causing punishment-by-network-effect to perpetrators.
Until recently, spam was a nuisance which people would grudgingly try and ignore. Now more people are actively complaining, and things are looking better. The article is very right about companies trying to make customers feel powerless; since COVID, when people had some free time on their hands, they started using some of it to fight against the "sludge" and hold companies accountable.