"Simon Lee: The Old Huntsman," rather than depicting the effects of social change, is, in a sense, an elegy for a specific individual who simply has grown old, and the effects of aging have been devastating. To be sure, there are indications that Simon Lee once wore the livery of someone important, but I think Wordsworth's emphasis in this poem is on physical, rather than social, dissolution.
The first three stanzas, for example, paint the picture of an active man in his prime whose overriding joy (no pun intended) was fox hunting. He loved the chase so much, in fact, that "he little cared/For husbandry or tillage;/To blither tasks did Simon rouse/The sleepers of the village." Wordsworth presents us with a vibrant individual, perhaps not the most diligent, but certainly a person alive with the joy of his favorite pastime.
The fourth stanza, I think, begins a somewhat elegiac tone, one of loss (by implication), for we are told that "And still there's something in the world/At which his heart rejoices," an observation that leaves us understanding that Simon Lee has lost something crucial to his well being.
The hammer comes down in the fifth stanza when we learn that Simon is not only in poverty but, more important, he's lost "health, strength, friends, and kindred, see!" This stanza certainly contains explicit comments on Simon Lee's social condition, and the reasons for that condition, but, again, the emphasis seems to be on the negative aspects of his personal condition. As with his health, which has disappeared, his larger world has gone, made explicit by the fact that "he is the sole survivor" of the past.
The next several stanzas consist of a catalogue of physical and economic dissolution, with his only support being a loyal wife who "is the stouter of the two" and does what Simon Lee can no longer do.
The denouement arrives with Wordsworth's recounting of the help he gave to Simon Lee in removing a stubborn tree root, but the important point at the end is Simon Lee's gratitude, "so fast out of his heart, I thought/They never would have done." Even in such physical and mental distress, Simon Lee, who would be defined by Wordsworth as a "natural man," overflows with genuine gratitude for a minor kindness. Unlike Simon Lee, in Wordsworth's experience, many men with "hearts unkind" would withhold their gratitude. The only thing of value Simon Lee has to bestow on his benefactor is heart-felt gratitude.