Is it really a must to for investors hold bitcoin for 8 to 10 years, before someone can see profitability in the investment?
Is not a must but a beneficial duration of investment to some persons because your invested money determines how long is going to be, for example you and I have a plan of getting $26k worth of Bitcoin and you started with the weekly investment of $100 and in five years you should be having nothing less than $26k in Bitcoin meanwhile instead of using the same amount you are using I choose $50 based on financial insolvent, so actually in the five years I will be having only $13,044 in Bitcoin while you have meet your target in just five years I'm still half way to it, so to get this I will have to give myself another five years to get there making it 10 years I have spent to achieve it, so actually this example is just a little explanation to show you that 10 year investment is not a must but with your plan it can take up to the years I have explained.
Of course, if you invest $100 per week for 5 years, then each year you would be investing $5,200, so after 5 years, you would have $26k invested. Yet you cannot know know for sure if the dollar value that you invested into bitcoin will be more or less of the amount that you invested.
We invest into bitcoin because we believe that it has decently good fundamentals to cause it it mostly be going up in value rather than down in value, yet we have no guarantees.... so we have to select our investment size in accordance with how much we are able to (and willing to) put into such an asymmetric bet that could potentially cause us to lose up to 100% of the value that we put in or that it could appreciate in value more than if we had placed such value in other locations - and there are variations of those scenarios... which we can make estimates, yet we are not going to have certainties about the values until time plays out and in the meantime, hopefully we are also securing our bitcoin in safe ways so that we do not end up losing them due to our own lack of proper care-takings.