Sorry Hartwerger, My post did leave a bit to be explained, and was sort of vague re-reading back.
I'll explain further.
My opinion of Outer Sleeves, is that yes, they will actually protect the LP itself, even though one might not be able to see immediately how this is.
Imagine this if you will, your LPs sitting on a shelf, rack, or wherever 9Hopefully in an upright manner, and as they sit, the dust accumilates. Two weeks, two months, two years, six years, etc. etc. Imagine if you will, the amount of dust landing on your beloved, and expensive LPs. If you live in a desert climate like I do in New Mexico, all the more reason for the Outer Sleeves.
Eventually, dust will get in, thus intruding into the inner Sleeves, and ultimately the LP itself even if you might think it won't. The other obvious benefit, is the protection of the LP Outer covers themselves.
When a person has just perhaps a dozen LPs, then maybe one might feel what's the use?, but when collections start numbering into the multiple 100's, I feel it's very wise to protect this investment as well as possible.
For years I went without, but for the last 10 years I haven't. I feel the Outer Sleeves were a very wise investment, and whenever I buy used LPs, they get the complete treatment, Last, or Disc Doctor Cleaners, Last Preservative, and always new Inner, and Outer Sleeves.
I know when I go to pull one of these LPs, even if it's a year later, all is fine, and spotless. Hope this helps, Mark