Want to use that development framework so that you can work faster? Want to use that library that provides some good function? Want to use that technology for a desired effect?
All these things are helpful and will do something for you. The cool thing is that in this world of open source they don’t cost anything, right? Wrong.
While it may be true that there might not be a direct up-front financial cost for acquiring those things (assuming they are gratis), it is blatantly false that there is no back-end cost for those things. Everything has a cost. That cost may be in the form of time to integrate, increased risk, footprint size, complexity, limitations introduced, bugs inherited, intellectual property liability or contamination, or something else.
Don’t misunderstand me, I’m not suggesting that you always avoid using things. What I am suggesting is that you always determine what the cost is, and evaluate if the benefit provided by that thing is worth the cost. Do not assume you can get the benefit without the cost.
Nothing is without some kind of cost. Nothing. There are some good deals, some bad deals, and some so-so deals. Just be conscious of what you get yourself into.