They don't need to learn about how to use a wallet before investing in Bitcoin but what will happen if they lack the knowledge on how they will keep their BTC safe when we're in the season where it is more important for people to hold their BTC in self-custodial wallets?
I am not proclaiming to know all of the answers, yet I know that it is a bit too much to proclaim that a beginner has to learn how to self-custody prior to getting started investing into bitcion.
Yes, it is preferred that a person holds most of his coins in self-custody, perhaps 90% or more, but still, self custody is not a prerequisite to getting started in bitcoin.
You have a point. A self-custodial wallet is not a prerequisite for newbies to begin their Bitcoin journey since they need to experience how it feels when buying some Satoshi. But they still need to know the key and important parts that will help and secure the Bitcoin journey, or else they may be victims of online theft, which always targets Bitcoin newbies.
This is one of the reasons why I consider investment in Bitcoin not to be something a newbie can rush into.
Furthermore if a person keeps coins on exchanges (or otherwise with third-parties) he should realize that he is running risks that he could lose some or all of those coins, which should help to motivate him to learn about self-custody and to employ self-custody.
Everyone is responsible for their own actions, including if they choose to remain so dumb as to keep all of their coins on exchanges, so even though I am saying that a person does not need to learn about self-custody in order to start investing into bitcoin, I am not recommending keeping coins on exchanges for extended periods of time or that it is a good habit to keep very many coins at all on any exchanges (or with third parities), I personally would not recommend any more than 10% of your coins being held with third parties at any given time, even though surely there are folks who are way more tolerant of various forms of third-party custody.
Ok. Now, I understand what you're trying to say. I just point out the statement because some newbies may misunderstand what you're trying to say.