When a show runs this long, the finale isn't just an episode, it's a verdict on everything that came before it. The Boys had years of build-up, a Homelander problem nobody seemed sure how to actually solve, and a Butcher arc that's been pointed at a cliff since Season 1. So when Robbie Fox teed up a huge week in the Basement, the finale recap was always going to be the headline event.
Robbie laid out the Basement's slate with the finale recap up top.

The recap dropped that night, and the framing told you everything you needed to know about how it landed. Robbie and Clem weren't just reviewing the episode, they were ranking Billy Joel songs and rewriting Season 5 on the fly, which is the kind of thing you only do when the actual season didn't give you enough to chew on.
The episode billing put the rewrite-on-the-fly bit right next to the recap.

The reaction wasn't isolated to MMB either. Eric Hubbs posted a one-line gut reaction that pretty much summed up the mood for a chunk of the fanbase, and by the next afternoon the main Barstool account was running a spoiler-filled review pointed at the same disappointment.
Hubbs reacting to the finale in real time.
The main Barstool account framing the finale as a letdown for a lot of viewers.

The most damning takeaway from Robbie's follow-up clip with Clem is the one that's hardest for the show to recover from in hindsight. If the finale renders a chunk of the season's plotting moot, then every subplot you spent weeks on becomes filler in retrospect. That's a worse problem than just a bad episode.
Robbie and Clem on how much of Season 5 the finale made feel useless.
Whether you side with the finale or with the rewrite-it-yourself crowd, the conversation around The Boys is going to look like this for a while. Long-running shows live and die on their endings, and right now the Basement is firmly in the camp that says this one didn't stick the landing.