In a harsh manner, one has to reflect onto one's capability at times. Obviously no one else can tell you what you can be because simply they do not know enough. But any individual will want to be truthful for his/her own sake. The advise is merely given as a 3rd party, recipient should ponder over it and assess if it is appropriate.
I was advising based on the following description
While I advocate 活到老学到老,it doesn't mean the way at which one will absorb at the age of 40-50 is the same as one whom is 10-20. Also the mentality/心境 is different.
AI and BIG DATA is a radically different field as oppose to the normal software engineering and system engineering. Based on the past 20 years experience of the said poster, his/her lowest lying fruit, IMHO, is cloud computing. Starting afresh to pick up all the necessary fundamentals to be successful in AI and Big Data is a rush timeline for someone whom is in one's 40s while mainly only experienced as a system engineer. Even software engineering will be a significant jump.
On the other hand, cloud computing is extension from system engineering with a good mixture of devops; hence the inclusion of a software engineering skill set. Future employers looking for a cloud computing certified engineer will regard his/her past experience as a system engineer a relevant skill set. AI and BIG DATA does not regard system engineers as prior skill set.
Does it answer your doubt to my recommendation ?