Four weeks is a very long time in a fermenter. I allow 7 days or so to finish up, and then dryhop (if it's an IPA or APA), and then package.
Once a beer is done, it doesn't get "doner". Usually, a beer will be fermented out in 3-5 days for the most part, and then once it's been at FG for a day or two or three, it can be packaged. I like to let it clear a little and then package it.
It probably won't hurt a bit to go a month, especially if you like the yeast character that results, but it's not necessary either.
I don't know that four weeks is a long time; it's more common than I at first thought!
The interesting thing is that if you take the general issues that many new brewers have, they seem to be based around similar issues: off tastes in the background, haze or cloudiness, minor infections (often actually off flavours or gunk that's still in suspension rather than infections), gushing bottles, etc.. Back when I first started brewing some 40 years ago, I experienced all these problems.
In fact, to a certain extent, they became the 'hallmark' of home brew for most as there wasn't as much information or support as there is today. Homebrew had a 'twang' that most people good notice. Even a great brew had it in the background.
Today I often encounter that same 'twang' in many beers I try. However, through very simple changes I finally got to the point where my own beer is consistently clean tasting, clear, well attenuated and pretty much free from problems or infections. The latter point is specifically interesting as I don't bother with half the faff that some others do.
In my experience, the single most important changes I made were in regard to fermentation. I keep notes about everything because I can be disorganised at best, and looking back the two which transformed my beers were control of fermentation temperatures and fermentation time.
Once I've made a brew it goes into the FV, yeast is pitched and then I walk away. I check for external signs of fermentation starting and once I see those I won't go near it for at least 4 weeks. I never open it or move it. I just leave it well alone.
Fermentation is so much more than yeast metabolising sugar into alcohol, and those extra days or weeks allow the process to finish. That simply does not happen after 5 days or even 10 days. I don't try to force anything; I don't cold crash, I don't secondary, I don't filter or use finings. I just let the yeast do it's thing with the wort.
After the four weeks I'll carefully check the FV. If the OG is right and the sample tastes good, I'll either dry hop into the primary or package. If it tastes a bit raw I'll leave it be for another week or two. I've never had one go beyond that.
The beer is clear, clean tasting and well balanced. That's every batch, not nine out of ten. If there are issues I usually know because it'll be a mash error or an ingredient problem.
I also tend not to have batches go bad, because I don't touch anything until the fermentation is well and truly over. The hops and alcohol are sufficient to fight infections.
It's very true that a beer might be drinkable if packaged after 5-7 days, but in my experience (and that's all I have to go on) the four week period has turned my average homebrew into spectacular beer that has stopped me drinking commerical offerings purely based on taste.
You're right that once a beer is done it doesn't get 'doner'. My argument would be that whilst nearly done is acceptable (and common) for many homebrewers, letting it get properly done is one thing that totally changed my beer.