So I would appreciate your thoughts on this... Are presales still profitable or I should just forget about that chapter?
imo, I don't think it's healthy to participate in every presale. Before the market became filled with too many scam projects, the chances of getting your investment back was probably 50/50, but at this point, I don't even think it's upto 30/70. I advice you stick to something else, except you have the money to waste.
I have also considered presale as a complete waste of time and resources, even as I had written before, presales this days has almost turned a pumps and dump scheme. Imagine a presale that was successfully completed on schedule, unfortunately they listed token below the presale price, with the thought that the market forces of the demand/supply rules will enhance the price growth as time progresses but it completely a wishful thinking.
Without marketing, promotions, project developments and upgrades, there is absolutely no way for many of these tokens presale token to grow.