Yes you are right concerning the fact that there’s no guarantee that bitcoin will continue to go down or up too . But base on past performance bitcoin has proven to be among the best investments so far , which as even made some folk to regret not taken action earlier.
So using discretionary is a smart move tbh , it will help you to keep track while managing your normal daily expenses, making use of dcaing strategy . So still I believe if one start investing now he or she will still end up with some good profit at the end.
You don't really need a soothsayer to tell you that Bitcoin will appreciate in the future. Look at this way, no serious traditional asset has remain the value it was many years ago, even though some growth are disappointing, they are preserve the value of investors but look at Bitcoin, even if today Bitcoin price goes to $60k today, nobody can say it's hasn't done well, the only downside is that people that bought at the top are going to be weak, that's the default feeling of the market but that's an opportunity to buy at low prices we have missed.
There is not assurance anywhere that Bitcoin is going to become a world class but it's our collective belive that is going to make it happen. For years now, the government tried blackmail Bitcoin in different form but they couldn't win the fight, they had no choice but to jump on the train and now they are hoping to have their reserve. The institutional fomo is hear and this is just the tip of an iceberg, we are yet to fully unlock the potential of the institutional investors.