We can not know which altcoin appeared in 2019 has potential. The crypto market is quite unpredictable to know for sure what projects will be successful, so we only have to choose a project that looks good from our own research and expectations.
I agree with you that we can only look forward to projects that we believe will achieve maximum results later, with the current conditions it is difficult to choose a good project because sometimes projects that we consider to be successful turn out to be the bitter nature that we think will not succeed will succeed in achieving the targeted results, for when we are all bounty, we really have to be patient in waiting for good and profitable projects.