Stay in cushy PE job or move to MBB consulting

Why don't you switch to another PE firm? You're in a fortunate position to have presumably landed this role right out of undergrad and I'd imagine that with your experience, you'd have a good shot at plenty of MM firms looking for Associates that knows how to do the job. Plenty of PE firms will be faster paced with more upside and more exposure to a variety of assets.

I hate to break it to you, but MBB is a lot of excel and PPT work as well. You're also even less likely to get rich in MBB versus in PE. If you can at least grind up into the mid-levels, you'll find yourself making pretty good money compared to consultants. 

Consulting often sounds sexier than it is. For those with little to no business background, it does have some benefits as it provides you frameworks to understand business/corporate strategy. It also gives you a good branding/network if you need that. Beyond that, it's a lot of travel, a lot of BS work, and ultimately, you rarely make that big of an impact on the company. Most folks leave after a couple of years because they want to do something where they're not just being paid to essentially validate or check an idea. Although I haven't been a consultant, I've worked with many in my time in PE and frankly, we pay consultants to do all the garbage work that we don't really want to do, but want a nice slide deck/packet to skim through and use in our IC memo. I've obviously referring to the consultants that are doing PE diligence work as opposed to F500 strategy, but my point is that it's rare that you're doing something as awesome as you'd think. 

I'd think a little harder about what you actually want out of your role, what you want to learn, and what you goals are from both career and life (in the short term). Would you be happier working way harder and having to travel and go into the office everyday? WFH 3 days a week is cushy. Do you feel the real lack of social camaraderie and are solving for that? Hell you're off at 7 most nights? Join a kickball league or go on some dates. PE is a pretty good spot to be in as far as white collar careers goes. To me, going back to banking/consulting is generally a trade down, unless you have a specific reason for it as in, you loved an old team you worked for, your PE gig is soul crushing, you're getting a big promotion bump to go into consulting/banking, etc. To me you're chasing the dream of consulting a little bit where in reality, you'll be working harder, getting paid less, and I think the social element will leave a fair amount to be desired.

Now with all that said, do what your heart tells you. If you talk to a bunch of people and really think that MBB aligns better with what you want, go for it. Plenty of folks find MBB pretty fulfilling and a mix of working hard, getting paid well, and having some semblance of work life balance (compared to banking and PE). Good luck with the decision.

Edit: There was a really good post written a few months ago by someone who went from MBB to MF PE and then back to MBB. They talked a lot about how MF PE was uniquely more stressful and more isolating whereas MBB had much more collaboration and was generally much more respectful of work life balance, which I think is a completely fair take. Do a little searching and I'm sure you can find it. That person might be worth reaching out to as well.