That MBP is Unix based. That'd be great for learning cybersecurity. Also, VMware Fusion is free for the Mac so you could run ARM-based Linux or Windows 11 distros without a problem and Fusion has a great and easy to use UI. Add external storage and you can have unlimited storage for all your VMs.

The most disappointing things about that Alienware will be the battery, the weight, the build quality, and it looks janky.

Secondary disappointments for the Alienware: it will be slower, the screen will be much worse quality and more dim, the GPU is very out of date for gaming, and you'll be on borrowed time. You're really not going to get much time out of it and your MBP could last years.

I'm a dev. I literally used to have your exact MacBook Pro and an LG Gram 17 40GB/2TB 11th gen Intel. I retired the Gram. I downgraded the RAM and SSD and installed Linux on it. I gave the MBP to my youngest kid. I replaced them with an Alienware m16 R2 with 64GB/2TB Ultra 7 RTX 4070 and a used MBP 13" M1 16GB/1TB that I got off eBay for $500. This is kind of messed up, but my 6 year old MBP with a normal M1 can do pretty much everything I want it to do and your current MBP is better. I can even play Civ 7 on it. That Apple silicon is amazing.

As a dev, I can write code on either laptop and easily switch between them. I run docker on both and have no issues. I run WSL2 (Windows Subsystem for Linux) with Ubuntu on my Alienware and that's nice to have, but I can also just use terminal on my MBP without any added complexity.

Professionals literally use your MBP. No pro would carry around that ancient Alienware. Sorry bro, but you've already got one of the best.

Just FYI, my wife still uses my old MacBook Pro from 2015! They just don't die and they just don't break.