A person does not need much knowledge to start investing in Bitcoin, only if he can acquire common sense then he can start investing. Common sense does not say that one needs to know much except that they are able to calculate discretionary income or not. If a person is able to find discretionary income then he can definitely start investing and at the same time continue to gain knowledge.
Moving forward in parallel is the best decision. For example, the first step is to start investing and after starting investing, continue to gain knowledge. Moving forward in parallel and simultaneously taking the necessary steps for investment. Whenever you wait for gaining knowledge, you may miss out on many buying opportunities etc.
I mostly agree with your main point that a new person does not need to study for years and become an expert in Bitcoin before investing their first $10 or $20. But I disagree with the idea that waiting to gain knowledge will miss buying opportunities. We understand which price is a great buying opportunity more clearly later. Today, someone may think $100k is cheap, but it may decrease even more later. Again, if $100k becomes $140k, then the current price will seem low. A good reason to start is not the fear of missing the perfect price, but to avoid having to be a coiner for a long time or wasting a lot of time waiting for the perfect preparation. Therefore, if you have the ability, you should start investing even with a small amount.
I agree with your main point that you don't need to be an expert for years before starting Bitcoin and that anyone can start accumulating Bitcoin with a small amount if they want. However, I see the issue of "missing the opportunity" a little differently. In my opinion, we cannot say for sure whether the current price of Bitcoin will be cheap or expensive compared to the future. Therefore, the main goal should not be to find the best price, but to create a Bitcoin accumulation system that can be realistically continued in the long term according to your cashflow, discretionary income and backup funds.
Even if someone has a small amount of extra money, they can start investing with a small amount; it is not mandatory to have great knowledge when starting. It is possible to gradually learn about Bitcoin and improve your financial management along with investing. That is, learning will continue, but there is no need to completely postpone accumulation to learn. For example, a person has not yet started investing in Bitcoin, having gained knowledge about investing, while his friend has accumulated more wealth than him by gaining knowledge as well as investing.