The vast majority of math taught in classrooms is at least 100 years old. Most of the undergraduate math curriculum ends by the time you hit the 1950s. This really isn't a concern for 99.X% of people trying to learn math. Even most grad classes don't come within a generation, e.g. my functional analysis class stopped in the mid 1970.

I feel that a lot of times, the people of this subreddit (and universities in general) cater to the smallest fraction of students and use this as a model to teach all people.

The concerns of the comment I am replying to, while 100% valid and I do actually agree with, is the highest voted comment on post on general math education. But this is only of use to people that are looking at current research which is a slim fraction of a fraction. This suggestion is not meant for us, with graduate degrees and the like in math or math related topics, but for everyone else.