Are there founders who didn‘t appear to work on one particular thing really long and then had a breakthrough, but were more tinkering with a lot of ideas for a while until something clicked?

Founder /kiwi-news, a decentralized Hacker News

yeah I remember Slack actually, they did like a browser online game or something

The Angry Birds people made a lot of games that were not very popular until they made Angry Birds which blew up.

Also Slack ppl were working on one product (can’t even remember what it was) and decided to scrap it completely  and focus on their side project (internal chat system).

i think of it more as a funnel process - start wide, tinker with a lot of ideas and narrow down gradually until it becomes a very specific thing and you're all in.

Look at the product inventor style founders for stories like this rather than the software VC model. That’s the highest density of pure tinkerers I can think of. 

However, it might be useful if you haven’t seen it to try this early Balaji mental model on to add some structure. 

(The Idea Maze formalized)

Slack is a classic example of an extreme pivot