[ible]

Trying to design for many unknown futures is expensive.

Changing in the future costs something.

Designing for future changes up front makes sense if cost(future change) > cost(future proofing)

SAAS? Do virtually no future proofing.

IOT, do some.

Space probe? Do lots.

Also, if you haven't built quite a few relatively similar systems, don't do future proofing without talking to people who have.