Diablo 4 will be launched on June 6 this year. I am very much looking forward to this boutique that Blizzard has produced for so many years.

I learned that the highest level of the Nightmare Dungeon in Diablo 4 will be adjusted to above level 100. Does it mean that our characters can grow infinitely?

The answer is obviously negative. Blizzard officially stated that the purpose of adjusting the maximum level of the Nightmare Dungeon to be above level 100 is to make the Nightmare Dungeon still challenging when players reach the level cap. This will test the limits of your 100-level buildings.

If you want to become stronger, the best way is to buy more powerful weapons, helmets or other items, which may cost a lot of Diablo 4 Gold, the battle is imminent and there is no time for you to get it, you can Buy Diablo 4 Gold at
https://www.iggm.com/diablo-4-gold.