"Will algebra even be 'relevant' in the future?": While jobs and their specific skill-sets may change over time, mathematics
won't. Twenty years from now, two plus two will still be four, and quadratics will still be either
factorable or prime. Whatever job you get will provide the job-specific training you need, but
to get that job in the first place, you're going to need some background knowledge and skills.
And to be able to keep up with progress, to keep on top of new skill-sets, to move up the ladder,
to jump across into new and better career fields, you will need the flexibility of a broad foundation.
That foundation includes mathematics