When a popular presentation tool sunset its product, the decks that were not exported before the shutdown date were gone. People who had built real work inside it lost it. That is a hard lesson, and it is worth holding onto, because the question agencies usually ask a document tool is the wrong one. The question is not only what it can make. It is what happens to your work if the company changes its mind.
The lock-in nobody prices in
Every tool that stores your work in its own format is also storing leverage over you. As long as the company is healthy and pointed in the same direction, that leverage never gets used and you never feel it. The trouble is that you only find out how locked in you were at the worst possible moment: a shutdown, a pivot, a price hike, or an acquisition that changes the roadmap.
Agencies feel this more than most, because the work is the asset. Proposals, contracts, reports, and decks are not disposable internal notes. They are the record of the client relationship, and some of them are legal documents. Losing them or being unable to get them out cleanly is not an inconvenience. It is a real loss.