Because you won't lose from HODLing, unless if you decide to sell your coins at a lower price or you end up panic selling. And the fact that you do nothing than just hold without thinking of trading or mining to secure profits, makes it less stress and less pressure. As long as you wait patiently while looking for the perfect timing to sell, then losses are far from happening.
HODLing is also a smart investment strategy because it gets rid of destructive emotions that will hinder the future profits of your investment.
You can lose from holding Bitcoin.
1) If you have a target on when you want to be out and it turned out to be a bad timing you can end up selling for loss, for example if you are the type that buy Bitcoin when it was at 126k and by first quarter of next year you need the money, bitcoin might not be back at 126k then.
2) You can lose your Bitcoin if you choose the wrong Bitcoin wallet even if its cold storage, so it's better to spend time on looking into the best Bitcoin wallet right now, you might hold and never look back and one day you finally decide to check things up and your wallet is empty.
I think OP should know that money that needs to go into Bitcoin investment must not be the type they will need after a year, because to some people a year after is a very long time already, it's best to investment you are willing to risk. People who invested in Bitcoin and used ColdCard must have a lot of regrets right now.