Can small investors actually make good profit with bitcoin?
Or are there other ways to make money with bitcoin as a small investor rather than just buy and hold?
If you are investing $1k at $64k, you are going to get $2k back when it reaches $128k, and you will then get $3k when it reaches $172k, because your profits are counted from the point where you made your investment. Unless you sell first at $128k, and then buy Bitcoin worth $1k again at $128k, you don't need the price to reach $256k to get $2k in profits from your investment.
Anyway, talking about the profits one can get from a Bitcoin investment with a small capital, you basically get the same percentage as others, it's just that the higher your investment is, the higher your profits are going to be in amount, but the percentage will always be the same. For example, if you invest $1,000 and get a 50% profit, you get $500, but if you invest $100 and still get a 50% profit, you will only get $50 as your profit. In this regard, your profits will depend on the amount you are investing, good or bad, that's a subjective thing based on your current condition I would say.
If my requirements and expectations for the profits is not that high, because I know my condition and how much would mean what to me, then maybe $50 would also be a good profit for me if I could only afford to invest $100 and got $50 as profit. However, if it's the other way around, $50 will surely look too low.