I'd definitely say IntelliJ improved my productivity. No one cared. If anything, management viewed it as a nuisance as they had to deal with the license.

Now there is demands to justify not using AI like this, but people don't care about details. Which AI tool I use apparently doesn't matter at all, even if there are presumably productivity differences between them.

Edit: typo

Seems like you should have a justification for introducing a new tool instead, no? There are thousands of other tools they're also not using, but we're not asking about those.