YouTubers pay monthly for screen recording, captions, clipping and scheduling before the channel earns a cent. One-time tools fix the cost of production at the price of a single video's ad revenue.
The tool this job usually means renting is TinyPNG Pro, at ~$39/yr + API fees — roughly $39 a year, every year. Shrinkray does the job for a one-time $19 — running locally on your own machine.