>There is no pressure to perform or participate in a hackathon

I guess you haven't had the pleasure of participating in monthly workplace "hackathons". Of course participation is optional, but it can look good on your promotion case wink-wink nudge-nudge.

They tried to do a hackathon at my company but after initial interest a lot of people dropped out so in the end it was cancelled.

I think hackathons could be fun but they should either be done independently from a company or do something that's not of any direct value to the company but something fun.

The trick is to not care about internal promotion. You can also get promoted as you change jobs.

Indeed as an engineer this is the best course of action in our industry.