Disclaimer: I don't like SPAs, and I think the "modern" web stack is a niche set of technologies that are being widely overused. (This is why I put "modern" in quotes.)

But I have worked with enough engineers schooled since React became popular to know that the "modern" Web stack basically is SPAs everywhere.

Incidentally, this same evolution has made SQL something of a dark art among programmers. It's good that the field is big and diverse and specialized! But also, there are tons of professional full-stack Web programmers who are functionally illiterate in SQL due to primarily using NoSQLs or ORMs.