There is another side to this coin: Figma's gain here is Adboe's loss. It doesn't make sense to use market-caps of specific companies as yardsticks of consumer welfare, which is the ultimate measure which antitrust actions seek to maximize.
The tradeoffs of allowing or preventing the merger are more abstract and counterfactual. We cannot know for sure what the world in which Adobe successfully acquired Figma would look like. Its natural to imagine concerns of Adobe simply killing, enshittifying or failing to improve the product - all things that still may happen under Figma's new corporate structure. Also consider the potential integrations with and improvements to Photoshop that have been missed.
That all being said I think Figma is an excellent product for the price and I have no fondness towards Adobe (though I've never really been a customer) and I'm glad that Figma exits as its own delightful product.
We can’t know what would have happened exactly, but can be certain there would have been less competition if Adobe had acquired Figma.
We can’t know for sure whether increased competition is going to lead to a better outcome here, but we can say with a high level of certainty that more competition usually leads to better outcomes.
The fact that this also turned out to be fantastic for investors is just icing on the cake. Increased competition in markets is a worthy goal in itself.
Fantastic for investors in Figma specifically, not so fantastic for investors in Adobe. My point is that the IPO price and subsequent price increase are not themselves proof (or even relevant) that preventing the merger was a good thing.
There most likely would have been fewer firms if the merger went through (though it could be possible that more competitors enter the market in that alternate timeline). Idk if that constitutes less competition necessarily, and competition understood as number of firms or something similar certainly doesn't always lead to better outcomes.
In the cases of "natural monopolies", consumer welfare is maximized when one firm is able to realize all the economies of scale because the benefits of mass production are so large that goods/services can only be produced at the lowest cost with sufficient consolidation. Utilities like electricity and water are often used as examples of natural monopolies.
You did say usually in fairness and I'd agree that increased competition usually leads to better outcomes. And we usually see multiple firms competing in any given industry without antitrust intervention.
It’s not proof that blocking the merger was good, but it does undermine many of the arguments against blocking it.
I’m all for the government getting out of the way of business, but we’ve seen a large amount of consolidation in many software categories.
Adobe’s market share is pretty extreme already in the creative software space, and I think it is reasonable for the government to step in to try to prevent further consolidation.
I agree with you that it’s really unknowable whether blocking or not blocking was a better choice. But if we only made decisions based on knowing the outcome, we’d never do anything.