I don't think it is quite so much a question of what survives being just the "second half" of the film but rather an abbreviated Kodascope home-view version (two-thirds the length of the original). It is a very pleasant unassuming comedy with a mild satirical note.
The fashion for high jinks on high buildings does not originate with Safety Last or with Lloyd but rather with Larry Semon in two or three comedies of 1918-19 (Dunces and Dangers, Humbugs and Husbands and Traps and Tangles) . Lloyd took up the challenge later in 1919 with Look Out Below. But undoubtedly Safety Last clinched the matter and by this time everybody but everybody was at it, so Devore is in good company that includes Buster and Tige, Farina from Our Gang and even the chimp Snooky. But it is true, as the other reviewer observes, that this example is particularly elaborate and particularly well done.
One very interesting aspect of the film, quite lacking in the films of Semon, Lloyd et al, is the extended political parallel drawn between the precarious acrobatics and the socio-economic crisis that was beginning to effect the US. Not only is the entire film about the difficulties of finding employment but the various sideshows - particularly the excellent Max Davidson as the opportunistic salesman - tend also in the same sense. It is not therefore just Devore who is haning by her fingernails.
African American Douglas Carter does not incidentally so much play "a black boy" as suggested in the cast-list here as a black "boy" in the condescending racist sense of the word. He is a fully grown man and has an important role in the film as the man sent by Devore's boyfriend to keep a watch on her, a role which he plays extremely well and it is an absolute disgrace that he was not credited.