256GB won't go very far if you're using pro apps or doing development. 512GB + cloud or NAS might be do-able.
...Logic Pro needs about 80GB for a full installation, with sound library.
...Final Cut needs 6GB of space to install
...I've seen reports of xCode refusing to install on machines with less than 40GB free
This is frequently-accessed stuff that you really want on your super-fast, local SSD. Also, SSD performance falls off a cliff if the drive gets anywhere close to being "full".
Just like the 8GB RAM thing, 256GB is OK for some people who just want "personal productivity" - but there would be no need to cut corners if Apple weren't charging such inflated prices - completely disproportionate to the actual cost of flash storage, even the fast stuff. 512GB or 1TB SSD is a no-brainer upgrade on any PC that was being used for content creation - except it's increasingly standard on anything near the price of a Mac.