My mom is a hoarder. I am really unsure of her type. I think she could be INFP or ISFP or ISFJ. Any of those. She is a mystery, keeps a lot inside of her though.
Anyway, she is very sentimental about EVERYTHING. She loves having the tangible reminders of what has happened, of happy memories, of people who are gone. Mostly it is sweet, she gets choked up sometimes even looking at a photo of us as children or something. But there are times it can be exasperating too. She also keeps a lot of stuff "just in case" - she can imagine a lot of uses for things most people would consider junk. She is very innovative and very thrifty. She tends to pay very little, if anything, for what she has acquired. But it becomes trouble when she saves way more of something than she needs/uses and it makes cabinets or drawers hard to open or hard to access. Another trait that is common to hoarders is difficulty in making decisions. I think it is because she sees so many options for things, and it's difficult for her to weigh which pots or pans (for example) she truly wants to keep, since there are situations where each pot is ideally suited. But the number of pots she owns way exceeds the number of pots which would be reasonably useful.
She feels a lot better getting rid of stuff if it goes to people who will use it. If she donates it to a charity or gives it to a friend or a friend of a friend in who can use it, that reassures her. She likes imagining the "new" owners using the item. I think she is also okay with recycling, if it's something truly useless or irreparable, but even that can be hard.