I agree the guide is too long and complicated.
Personally I have never verified a pgp signature from a file. (I am almost shame to admit lol)
However, I feel safe enough just by downloading files from the official website (just check social media and see if the links from there matches the address you have). I always double check everything as well.. addresses on device , on the website, etc.
It is like a basic common sense, however few people do .
All things are always complicated at beginnings.
For crypto newbies: How to get a bitcoin address? How to send bitcoin to other people? How to install a bitcoin wallet? Which wallet to use? What are differences between public key and private key? How to backup and recover wallets from seeds? How to do KYCs? And more. All of them are complicated.
I had same feelings when I joined crypto in the late of 2017.
Another example is account in the forum: How to secure it? How to sign a message to use as ownership-proof? Yes, it's complicated for guys don't know how to do.
It is unnecessary to sign a message for above purpose before one realizes account can be hacked and without a sign message the recovery will be more difficult and takes more time. Then, they will do it.
The same thing with wallet verifications, IMO. The more repetitions we do verifications, the faster we finish and the more comfortable we feel about wallet verifications.