It's hard to say exactly, it's like noticing when something is CGI in a movie. It's just kind of off.
The first few sentences gives it away for me. There's also the filler words.
Also the way it rephrases the sentences. You have:
there's always that one piece of software, that one perfectly tuned instance, where if it so much as hiccuped, you'd be ready to throw the entire homelab
Then again:
what's your absolute, non-negotiable, 'i will personally visit the datacenter if this fails' self-hosted application
It's also possible they just write like a bot.
I used to use an old Intel NUC with a HDD enclosure plugged into the USB 3 port as a NAS. Ran the *arr suite + Jellyfin on the internal SSD and stored all the media on the HDD and it worked fine. You should be good