+1 to EU and Iliad, which arrived on the market in about 2018 and started providing 9,99€/month mobile internet plans forever, but FOREVER for real. I still have that plan.
Yes, there are people I know who are still paying the same price Iliad offered at launch: 5.99€/month for unlimited calls and messages, and 30GB in 4G+. That price was basically half of what all other available providers offered at the time.