Well, I wouldn't say I have a beefy car or a beefy sword: there's some historical bit of linguistic connection that seems to have caused people to describe a server with the adjective "beefy", rather than "powerful", "hefty", "stacked", or... "chonky" ;P. Coming up with some options, I think my favorite might be "cranked"?
The first definition for beefy from Merriam-Webster is: heavily and powerfully built .
As someone who's had to rack some pretty heavy servers with lots of GPUs, CPUs, NVMe drives, and RAM, that turned out to be quite powerful, I'd say "beefy" is accurate.
https://www.merriam-webster.com/dictionary/beefy
Side note edit: hefty and chonky don't tell me much about power. Stacked is usually more about a team or group of things (and for individuals, I'd rather not see it).
I wouldn’t describe a corvette as beefy but I might call its engine beefy and i would definitely call a diesel truck beefy.
I think servers, especially bare metal, are in the category of grunt and raw power. Beefy feels right.
If you would suggest a word that would make a better substitute in this case, that could move the conversation forward, and perhaps you could improve the aesthetic quality of posts about leaving the cloud.