At the risk of weighing in on decisions that are well above my pay grade: whoever mentioned to you that fronted adverbials are not all that significant in n English but seem to be all the rage now is lying to you.

They have been there. /1

And the grief that people are spilling on social media about teaching these things to primary school children is confusing.

Teaching children how to consciously structure their sentences empowers them to use language with intent. /2

Teaching them to consciously structure their sentences empowers students to see how others use their language with intent.

Better writers should make for better readers.

Better readers should make for better thinkers. /3

And teaching grammar explicitly (including the apparently beyond the pale fronted adverbial) is fundamental to this.

Most of the time, we don’t want students fumbling in the dark.

There endeth the rant. /fin