Author here, that's a great question. I only host a handful of services on the VPS, including Nextcloud. I was mostly interested in storage, not so much in compute power.
Netcup offered VPS with 1 TB of storage for €30 / month back when I subscribed. The server has always been oversized for my needs, but that was the most financially interesting back then.
I recently switched to another ISP at home that gives me a fixed IP. I decided to move my services at home to shave off the VPS costs. Since I already had a Raspberry Pi 4, I only had to buy a SSD and an enclosure.
While I loved the sleuthing, I did not get why the comparison had to be between thise extreme ends of the spectrum.
Why not test a small extra cheap VPS, or, as the author does in the end, a somewhat normal PC at home?