Buying bitcoin for long term investment is not risky, the risky behind it is where you save the bitcoin. If you buy in centralized exchange and leave them there, you are risking your money with exchanges that may go bankrupt or get hacked anytime.
Buying altcoin is more riskier than bitcoin. You don’t need any strategy to buy and hold bitcoin I don’t know why you are saying that investing without any strategy is gambling.
Little disagree with your opinion about long term investment in bitcoin is not too risk, actually all investment kinds short or long term always has each risk and depend on our self how to minimize risk with stop loss feature or reinvesting more during price have been dropped. You can memorize with bitcoin price last two years when drastically dropping under $20k as long term investment had get risk their values of assets investment decreasing drastically but get positive side become long term holding our assets can recovery as well possibility and bitcoin success return to to higher price give us much profitable.
I agree with what he said, if you invest without knowledge, without strategy and only rely on luck or other people's advice, you are like gambling. Investing in bitcoin is the same, you will not be able to hold bitcoin long term and safely without basic knowledge or understanding of it. If that's not called gambling then what is it called?
Knowledge is most important factor to be success for investing in bitcoin, although bitcoin promising more excited price years by years we musk understand when the right or best time for investing in bitcoin and how much percent allocated investment every time get moment bitcoin in lower price. Some experience trader they left more than 50% preparing for buying back when bitcoin going dump and they can accumulate another lower price of bitcoin.