Is a possibility and has its potential. I believe best Investments are subjective.
If we talking about increment since inception or listing then I can say it's the biggest investment or one of in recent years.
Real Estate is still the Now and still in the future
One of our basic needs as humans is shelter
So like Real estate is essential do is Agriculture.
Bitcoin helps in creating and protecting of wealth without the need of a third party.

Bitcoin at the moment has certainly the potentials and even one of the most influential investments so far.  So it's not really impossible to see bitcoin as the world's biggest investment in the future. However, there are also certain factors that until now become a struggle for bitcoin to reach the said phase for bitcoin. It's volatility alone is indeed a big threat for global adoption. It's regulation and legal framework is still not highly established. But if only bitcoin will continue to be seen as a digital gold because of its increasing store of value, and having financial institutions to back up bitcoin, then it won't be surprising for bitcoin to become the best world's investment in the future.

By comparing it with other investment properties, some people already regard it as one of the best investment assets so far, but if we are to look at market capitalisation, it's still a bit far behind, but it can get there; all that's required is more force on adoption and an increase in price, then it can obtain that biggest investment as for the best; it's already the best depending on who you ask.

I think the whole best investment thing is kind of relative, you know? Like, investing always has some amount of risk no matter what.  Bitcoin is still pretty new thing and real estate has been around longer though and people usually think its more stable

At the end of the day, the best investment for someone comes down to their personal situation.  Theres no one size fits all answer.  For some folks Bitcoin works, and for others, something like real estate makes more sense.

I was actually thinking the same with Op, but one thing we should know is that nothing last forever I think we are still in the era of bitcoin, well if you ask me about bitcoin being the biggest and the best investment in the world? I must say that the question is very technical because if you look at other investment out there you will discover that, that same risk involved in bitcoin investment is also applicable in other investment. is it the price not being stable? You know this also happens in other investment out there just as it is in bitcoin investment,  so I think bitcoin is the best investment so far.

Both the terms "biggest" and "best" are subjective that's we can't answer this accurately.
Biggest in what? Market cap? Users?
Best in what?

For me, real estate is still at the top when it comes to investment. Yes, the capital that you need in real estate is quite high (unless you will invest into REITS), but the reward in the long run can be good and it can give you passive income through rental income. As for Bitcoin, it can go as high as real estate since it's appreciating in price because of the limited supply, but right now, there's no certainty on it yet. Bitcoin is still on the adoption stage so thinking like this is for me, a bit early.

Can we just not think about this first, and think about the adoption rate of Bitcoin around the world?

Of course it will, I think in the next 10-20 years Bitcoin gonna become the world biggest investment, if we talk about the market cap. Right now Bitcoin market cap is $2 Trillion, if we assume every 4 years the market cap will be doubled, it took around 16 years to make it $32 Trillion, higher than gold market cap.

Bitcoin is the best investment as long as you hold the real Bitcoin in your wallet, not the ETF version or hold in CEX.

Yeah, in the next decade, we would cherish the price we've got currently.
Those who understand it now will be in the best position in the future.
 
And as with uneng - for me, it's the most stable investment out there.

That time would provably came.

If you see this list https://en.tempo.co/read/1942728/top-10-most-valuable-assets-in-the-world-2024-bitcoin-placed-7th you will see that Bitcoin is breaking records to records and provably that it will surpass those assets at the top on that list.

Although right now we can say that we are still early on adaption state. Imagine what would happen to it if this is been recognize positively and those plans to make it as countries reserve would happen? For sure huge demand would came and those price increase that will happen to it will be beneficial to all Bitcoin investors.

It already is the best investment, it has been the best performing asset over the last 15 years. To be the biggest investment in the world we need to see the market cap surpass Golds. It will happen but it might be in the 2030’s.
Stay calm, humble & stack sats, safe in the knowledge that Bitcoin is the best investment that exists.