This is the same exact situation for me (though I think I'm older).

I was an engineer on Wall Street and then was working as a senior engineer at Google for over 4 years when I started my executive MBA at an M7 school.

Realistically, as an engineer at Google, in most cases, you will get more value out of the Google brand and experience than you will get out of most MBA. This is especially true with your stated goals (PM/entrepreneur - similar to mine). If you want to switch from eng to pm, you'll get more credibility from a PM experience at Google than from a MBA. In addition, Google has an internal program that allows engineers to rotate through as a PM for a short period of time.

In addition, as you become more senior as an engineer (L6+) at Google, you have more input into product decisions. Even before then, as a Google engineer, you can maneuver your role into a more hybrid pm/eng role.

Lastly, the Google and Google alumni network is quite extensive. It gets you access to a number of people by dropping the Google brand. As a Google engineer, you can pretty much get your foot in the door of many companies. (There are a number of Google alumni and entrepreneur networks/slack groups that you may want to look into. If you don't know them, PM me)

So, why did I do the MBA and what are my thought on it? For me, I went into it knowing it is most likely a negative ROI. As mentioned above, I can increase my career value by growing at Google or any Tier 1 tech company.

The reason I am getting my MBA are:

1. Personal pride. For the longest time since college, I've always wanted to go to b-school. I have always been interested in the business side of companies and wanted to grow in that area. It's an irrational reason, but I was willing to do this at any cost.
2. Entrepreneurship. I wanted to leverage the MBA to satisfy my startup itch. Again, this is an irrational reason for a MBA. As Sam Altman (YC) said in an interview yesterday, you're better off working a month at a startup than getting an MBA. (Take this with a grain of salt, there's an anti-MBA bias in Silicon Valley). Halfway through the first year, I left Google to focus on my startup.
3. Expand my professional network. This has surpassed my expectations from the MBA program. Since I'm in the executive program, the caliber of the people that I am in class with is extremely high. We have formed tight bonds that there's few in the class that I wouldn't go to bat for. In addition, the alumni network has been an incredible resource. I've gotten in touch with a number of entrepreneurs and VCs just in tapping the network and sharing that mutual connections. For me, this is the biggest ROI on my MBA.
4. Academics. The classroom material is very interesting and relevant. You get out of it what you put into it. You can learn the same lessons from actually doing it, but the MBA gives you the basis in a concentrated period of time.

All in all, I am extremely happy with my decision to get my MBA. The key here is that you need to know your reason for getting it and making the decision yourself. As I'm trying to convey, being an engineer at Google has as much value as a certain level of MBA program. Just make sure you choose a program that meets your goals.

Anyway, if you want to take further about this, feel free to reach out to me.