Bitcoin is still a gamble. Plus, there's no way to predict that someone might actually develop something that is better than Bitcoin, and eventually we might come to that.
What is the meaning of better? There are coins with biger blocks, faster transactions, cheaper coins, more coins in circulation, less coins in circulation, centralized, anonymous, with partnerships, with councils, with CEOs, with market strategies and plans, with apps build on them, with side chains, with forks, without forks, with coin burning, without burning... All of them fail when compared to bitcoin, all of them have lower market caps, less users, less trading volume, less real transactions.
At the moment, it's by far the best, and the most promising in terms of increasing your personal wealth, but it's not bulletproof. We're still going to face challenges in the near future, and well into the future, and there's going to be a element of risk that we aren't successful as we'd like to be.
I think investing into Bitcoin not expecting some of these challenges is risky in itself, and will likely lead to panic when we do hit these challenges. So, while Altcoins are definitely a lot more risky, Bitcoin isn't invulnerable to issues itself. Since, I've been involved we've had to solve several issues that have popped up, and while none have them have seriously threatened Bitcoin up until now, they have affected people's perception of Bitcoin, and therefore lead to higher, and lower rates of adoption.
Aren't you describing every single investment on the planet? They all have issues, they are all risky. Fiat is risky and it has issues and so do bonds. Trusting the government is risky, holding money under the mattress is risky, owning physical gold is risky, moving to a different country is risky, buying a property is risky and renting it out is even more risky.
When we compare bitcoin to everything else, I'd say it has a pretty high chance of surviving and becoming something much bigger than it is.
All of us should think about the question. Would you feel better putting your savings on a bank account so it can lose 10% a year for the next 20 years, buying a house with it that will tie you to a country with taxes and all the maintenance that this house needs, or buying bitcoin.