For short tasks — rewriting an email, explaining a concept, summarising one page — free tiers are enough and you should not pay. The three things that break a free plan are: long documents (context limits bite), sustained use (message caps), and the better model behind the paywall.
If your work is one of those three, plan for a paid plan on the tool you use most rather than spreading three free accounts across three products — you'll spend more time re-pasting context than you save.