Bitcoin has been on a constant decline in value ever since 2018 started. Most say it has been a result of government regulations, others say that whales are manipulating the market, and some say that it's the result of FUD within the cryptocurrency markets.
I'd say that it's neither of any of the options.
While perhaps some government restrictions placed on bitcoin and third party bitcoin services are contributing to the bear market, they are not the root cause. I believe that a bear market was simply imminent, and was only a matter of time before it happened, because of the fact that markets rose so much during 2017 that it was becoming unsustainable. Thus, a period of corrections and dips were only natural, and this has been seen countless times before.
Nevertheless, do you think Bitcoin will hit a trillion-dollar marketcap in the future? How far do you think this is from becoming a reality? I would like to know your thoughts about this.

It's going to happen sooner or later. People tend to write this off as some kind of far sighted prophecy, but it really is not. We've seen a market cap that was around 30-40% of that figure already last year, so it's closer than people think.
With a limited supply and growing adoption that we've seen that will continue well into the next decades, bitcoin is bound to be more valuable in the long run. It's simple economics, supply of bitcoin isn't going to get much bigger since it is emitted in a limited manner, while the demand of coins will go up over time as more merchants accept it for payments. That's not to mention the imminent inflation that will debase the value of fiat as well, which would mean that when bitcoin is traded in relation to fiat, its value will rise in the long run, at least theoretically speaking.