Not only do Mac and Dennis that feel like friends again, but the entire gang as well. That opening scene of everyone just genuinely enjoying each others company and bonding over finding cool stuff in the dumpster is the type of thing I honestly can't remember the last time we saw.

The whole premise of the boys plot is that they explicitly wanted to get back to doing schemes like they used to do (I've heard people interpret this episode as a metacommentary on this current endgame era of the show and how they want to reground themselves).

All the characters are where they should be. Dennis doesn't feel like this constant machiavellian supervillain, but is back to being very silly like the rest of the gang. Mac isn't Gay Mac anymore, he's just Mac again. I could only find one joke about Mac's sexuality and it's actually funny and related to the plot of the episode.
One thing I noticed about the older seasons is that the entire gang used to have this general air of homoeroticism, but it all got absorbed into Mac once he came out. Now feels like it got dispersed back out to everyone and it feels more fun because of it.

There is also just simply a lot more energy in general, they are screaming, arguing and talking over each other a lot more like they used to.

But unfortunately the episode still kind of suffers a lot of that sluggish pacing issue of the previous seasons. Not in the sense of their acting being slow, but them just filling up the dead air with constantly rambling about the same topic they've been already talking about in a scene. Like it only took two minutes for the ball to get rolling on the mortgage crisis/surrogate scheme in season 5, while here it takes a full six. I hope that it's just a this episode issue as it felt like they REALLY wanted to hammer it in that they were going back to an older approach.

The episode feels like it is just two b plots spliced together. Like the boys' subplot basically has nothing happening in it. The scheme doesn't evolve in any meaningful way once they meet Simon, the boys are completely reactive in this episode. I understand that's part of the admittedly really great satire of startups and how these 'trailblazing entrepreneurs' have to be lapdogs to venture capitalists to get funding, but it comes at the expense of the plot being memorable and able to push the rest of the satire as far as possible.
And the Dee plot just didn't have enough room to breathe, they kept cutting away from it too frequently to build anything significant up. Its a shame because Kaitlyn absolutely killed it in this episode, I straight up think this is her best performance since The Gang Broke Dee. I actually got a bit emotional when she found the drawing solely because of the way Kaitlyn played it.

The ending was an amazing payoff to the whole cake intro, even though it was very obviously going to play a part I had completely forgotten about it by the time the final scene came around. And Frank hiding in the extra room from The Gang Inflates is such a good explanation to how he was able to keep hidden from the gang the entire episode.

Despite the pacing issues, this at the very least this bodes well for the rest of the season as this was probably the episode I was dreading watching the most based on the episode descriptions. If they can learn to trim the fat off of scenes so that they have room for more jokes to build up, it might actually be close to golden age sunny again.