I'll add my anecdote here: I bought a Tern Verge and the accessory bike bag about 1.5 years ago because I imagined taking the bike on the train or public transport and because I lived in a small apartment. With the bag, you can take it like any other bag, but without, even if folded, you need to pay extra and place it in dedicated bike spots.

Now partially that's just my laziness and trajectory in life, but I haven't used the bag once (I'm not even sure how to use the bag, it's...complicated?). And the bike was folded only once, when I moved.

About a year later I bought a road bike because I wanted better climbing and longer distances and more comfort. Ultimately, for me the folding bike - while great fun in general, it's fast and agile - was kind of the wrong choice.