Small pieces of code replacing long pieces of code is a daily routine.

But more on the topic, i would say calling ffmpeg as external binary to handle some multimedia processing would be one of those cases where simple is better.

Generally, I would say that implementing your own solution over an external one(like a library, service or product) will always fall under this umbrella. Mostly, because you can implement only what you need and add other things that might be missing or adjust things that do not work exactly as you'd needed them to, so you can avoid any patches, translation layers or external pipelines.

For example, right now I am implementing my own layouting library, because Clay bindings for Go were not working or manual translations were missing features or were otherwise incomplete or non-functional. So I've learnt about Clay and on what principles it was built, by Nic Baker, and wrote my own version in Go. It has little over 2k lines of code right now and will take me about two weeks to finish, with all or most features I wanted. Now I have a fully native Go layouting library that does what I need and I can use and modify it ad infinitum.

So I would say that I equal a "dumb solution" with "my own" solution.

PS: looking back, when I used to work in advertising/marketing/web agency, we used to make websites in CMSs(I did Drupal, colleague did Wordpress). Before my departure from the job in general, I came to a conclusion that if we would be using static website generators, we could have saved unimaginable amount of work hours and deliver the same products, as 99% of clients never managed their websites as by nature of the job, we were doing presentational websites, not complicated functional ones. And when they did, they only needed such tiny changes that it would make way more sense to do it for them for free upon request. For example, imagine you charge someone 5000€ for a website that takes you two months to ship, because you need to design it, build it functionally, fit the visual style and tweak whatever is needed. If you'd use static website generator, the work would take two weeks - a week for the design and a week for coding the website itself. Now you've saved yourself 6 weeks of work while getting paid the same amount of money. Unfortunately, I did not have a chance to try this out and force a new direction at the company as it was at the end of my career.