This question is fascinating. Everybody wants to keep one's language. But do you think yours is going to survive?
The Washington Post posted an article several years ago and it suggested that people would choose their languages based on their interest. For example, if you are interested in making money, it would be better to learn languages of BRICS. However, I feel the view is very short term and only for temporary. I want to know the ultimate state of language on this planet on global scale.
The article also mentioned the concept of 'Hub Languages', which are the languages to be used as hubs where translation is needed. It seems hub languages are more valuable as tools and then they can be the dominating languages in the long run.
There is another article by J. K. Buda studying 'language choice' in a situation where several languages are options to be used. The article deals the issue in a relatively small scale, but it may be applied in a global scale too. The author considers two major categories of factors: preference and constraints.
One of the principles for language choice is 'majority win' and this is based on constraints. Obviously, you want to choose the most common language in the group to get better communication. There can be another factor based on preferences. Many people identify themselves with their language. In other words, their language is a part of their identity and they don't want to give it up as much as possible.
If your mother tongue is not a hub language nor a language spoken by many people on this planet, you may want to change your language in the long run. Or you may want your children to change their language. Which sounds quite extreme but why not use the better one while you have freedom to choose?
The Future of Languages by The Washington Post:
Language Choice by J. K. Buda: