Shakespeare puts little and fleeting value on human relationships in the sonnet.
Step-by-step explanation:
The sonnet 29 begins with these lines:
When, in disgrace with fortune and men’s eyes,
I alone beweep.
These lines show him alone and lonely and in want of comfort but he is also saying here that he does not see human relationships as permanent.
He then develops this theme throughout and when the muse himself is mentioned in the poem, the poet only ascribes value to him and nothing else.
Everything else can go on in passing as long as he has his beloved to love and to keep him there and sane.