Beginning sentences with a needless "So". How did this scourge become so popular? [duplicate]

Solution 1:

Beware the Recency Illusion. This use of ‘so’ is not new. Shakespeare frequently uses it as an introductory particle, as in this from ‘The Rape of Lucrece’:

So so, quoth he, these lets attend the time.

Swift similarly uses it in his ‘Journal to Stella’:

So you have got into Presto's lodgings; very fine, truly!

Its current use to mean, in some cases ‘well then, in that case, very well’ and in others ‘but then, anyway’ reflects Yiddish idioms. Its first recorded use in this sense is in 1950:

Miriam returned after 11.30.‥ ‘So where did you go?’ Feld asked pleasantly.

Solution 2:

It's simply part of the expanding stable of pause-fillers: um, ah, well, like, mmm, yah, and so on. Anyway…