Totally depends.
Some people achieve a base weight as low as 4.5kg, others carry up to 40kg of stuff.
Personally I’ve usually ended up around 10kg in two 20l rear panniers with the tent on top of the rear rack.
Weight is important. Don’t bring stuff you could easily do without. I’ve seen people bring full sized pliers, hammer, rolls of duct tape, heavy 3 person tents (>4kg), a change of clothes for every day, bottle of wine etc. etc.
It can quickly add up to more than 20kg which will make ascends a chore and carrying the fully loaded bike will be very difficult.
When you bring a lot of stuff you also need more bags/panniers and a sturdier, heavier bike.
Make a pack list. Weigh every item. For every item evaluate if you really need/want it or if there is a lighter option.
Edit: Where I’d err on the side of caution and comfort is warmth of clothes and quilt/sleeping bag. Don’t bring your 10°C comfort summer sleeping bag just because it’s 200g lighter than your winter sleeping bag if you expect temperatures to go down to 0°C. Don’t hesitate too much to bring your 400g down puffy if you expect temperatures to be cold at camp. Same for water and food. Especially if you are in remote areas and can’t just ride to the next hotel if the night gets too cold or to a supermarket if you run out of water/food.