The recent very active moves to clean the site up and prep for this IPO have had a detrimental community effect in the sense of disgruntlement, but I would wager have been excellent in making the site more palatable as a business.
Virtually none of the reddit-alternatives that all spun up in the wake of this mop job have taken off. So assuming our gut feeling is right that reddit engagement is down, then overall engagement on all reddits is down and users have entirely moved to other social media styles entirely.
There's the other angle on this, that engagement is down, but it was calculated to get rid of mostly users who cost reddit things, or are of an undesirable user population (troublesome, illegal, etc.) And what's left is mostly a user class that maximizes the monetary value that can be harvested.
There are huge and obvious areas where reddit can better monetize the site if they wished, and I would guess that it's going to happen. Reddit has a very long history of doing a bunch of different experiments with the site, and an influx of investment to properly analyze and then monetize the more successful ones is my guess as to what's going to happen. The recent drive to vacuum up and sell data to LLM companies is serendipitous icing right now.
There's also the huge opening that's happening right now with Twitter, where with a few chess moves, Reddit could very easily turn into or pick up the population of exTwitter users who find the current ownership trends so toxic they don't want to be associated with it any longer, but don't have a platform with a built in non-friends public sphere to turn to -- which is why Facebook hasn't been able to really tap into that market gap.