The total number of BTC ever to be in existence is capped at 21 million. This scarcity has made it valuable similar to precious metals like gold, silver, diamond etc.
This is an incomplete statement. Like gold, silver, etc. Bitcoin is not
only valuable because of its supply. Instead the capped supply is a contributing factor, the main factor is its utilities. Otherwise a shitcoin like 42coin (supply cap is at 42) and a lot of altcoins have capped supply too but they are useless which means they are never considered for purchase let alone have any increasing value.
It has been seen that people are more confident to invest in BTC than other crypto currency in the world.
People choose bitcoin over others because bitcoin is useful while others aren't.
BTC is the best crypto to buy and be relaxed that it won't drop to the point of you losing your money
You need to add a "in the long run" at the end because bitcoin drops in short term a lot.
BTC will forever remain the greatest crypto currency in the world.
Forever is a long time. Any new innovation has the potential of competing with Bitcoin and surpassing it. The thing is that in the past 15 years from Bitcoin inception, there hasn't been any significant innovation worthy of attention or capable of competing with Bitcoin.