Anything can happen theoretically haha. Yes absolutely theoretically bitcoin could drop to zero. That would involve everyone in the world deciding they don't want bitcoin and every single person stops buying.

Any investment can theoretically drop to zero. The practicality of bitcoin dropping to zero....well thats about the likelihood of waking up to find Apple is out of business tomorrow. Speaking of which, any stock has a much much higher chance of dropping to zero than Bitcoin, because Bitcoin is a currency owned by tens of millions of people and rapidly growing based on its fundamentals, while stocks involve the company staying in business and any company can go out of business if it starts failing to compete.

So its kinda of silly to say Bitcoin could drop to zero when its less likely to drop to zero than any stock which are considered "safe traditional" investments.

Also theoretically bitcoin could go to a billion dollars, and given fiat inflation over time, thats far more likely than it ever dropping to zero because reaching a billion dollars is simply a function of time. Doing the math, if all bitcoin did from here on out was keeps its raw value (stay at $43,500 in 2024 dollars, only going up by how much inflation there is in USD each year) and if we assume 3% long term USD inflation, bitcoin would reach $1 billion USD in 340 years simply as a function of USD losing value. I'd say its just about infinitely more likely bitcoin will be worth a billion USD in a few centuries than it being worth zero.