Why is it good that no more can be printed though? The value of all total goods in existence is not fixed, so why a currency where you don’t know how much you’ll able to buy with it in the future?
Not who you asked and I'm not a fan of BTC, but generally a fixed quantity of measure is helpful when trying to evaluate worth.
The fixed value acts as a measuring tape against objects, but instead of measuring length you measure value. When you measure to cut an inch of wood, you need the measuring tape to keep the length of an inch constant. If an inch were to shrink or expand at will it would be difficult to figure out how much wood to cut. Because BTC is infinitely divisible it acts like a retractable tape, allowing for as much room to measure as needed.
>why a currency where you don’t know how much you’ll able to buy with it in the future?
A fixed quantity helps with this. If your currency is free-floating and relative to others you can enter into different periods of relative purchasing power. Zimbabwe, Japan, Wiemar Germany, and Venezuela are all popular examples of floating currency behavior which can oscillate wildly.