they tell us to keep only that which is necessary and makes us happy
I think there is more to it than that. Things that have a purpose, a value, sentimentality, a uniqueness / rarity etc in my opinion are not hoarded items.
I have a lot of stuff, I live on a 7.5 acre of hobby farm, I have equipment, mowers, whippers, fencing materials, a tractor, trailers, and several cars ... the workshop in the garage needs to be better organized. I do not consider myself, and our country lifestyle to be worthy of being defined as hoarding.
My city slicker minimalist children (2 of 3) certainly think that there is too much stuff. I don't care. It is easy to get rid of OTHER PEOPLE's stuff, but it takes a bit of effort to get rid of your own stuff.
DUE to medical reasons, an accessibility renovation, and splitting our house in half to accommodate an additional unit, I currently have 50 years of HotWheels and 50 years of Model Railroading, many tools, fasteners etc mostly stored in totes in the garage. That does not mean that I just need to get rid of those items . When I pare down some of this stuff, it will first be organized, valued, and sold... not just tossed or thrifted. When my car / train buddy passed away in 2018, I was able to buy his 100 drawer fasteners cabinet for the garage. I am repurposing the contents to my priorities, but it is a great storage unit for 1000s of hardware bits.
Organizing the stuff, and using the space efficiently, will make all the difference. That is the first step in de-cluttering. There are also several dump runs that ultimately follow
.