It’s clear that you need to increase by betting on your BTC. But in most cases, you lose more than you win. Therefore, this method is more fun with funds that you do not mind losing. Better to invest in some budding project.
As I said, I don't recommend this approach and I know a lot of people would agree with me including you.
As you said though, it is also a good approach since you will be able to start with a small capital and you could just trade that to Bitcoin but it also has a con. You never know what will be the best project to choose from, in this community, scamming is not new and projects that have a goal to scam their investment is a thing. Better gather information first, educate yourself and always remember that you also need money if you want to be successful here.