I enjoy TayTim, Larry Stylinson and Paul/Faul McCartney all pretty much on the same level. And I do think there is a very high degree of similarity between Hiddleswift and Larry as media phenomenons in that they are interpretations of relationships that were very much played out in public and for promotional reasons.
What's different is that no-one is willing to die in a ditch, live on LA time or give up their job to try and prove that Paul Mccartney is dead or that Tay and Tim weren't really dating. For some reason Larry Stylinson struck a chord with people who take it enormously seriously - in part I think due to fanfic which means that people's mental landscape is constantly taken up with Styles and Tomlinson banging each other. I know you can get fics on anything and I think a pp confessed to reading Tim fanfic but it's just not on that level. I'd put Robsten in this category too.
I do think though if Tim and Tay had gone on for 6 years rather than 3 months, then there might be more comparison; there'd be many fewer mildly-amused-not-invested-spectators like us, some vehement truthers and something that was widely believed as reasonable at the start (Tim and Tay is a fauxmance; Styles and Tomlinson are in a relationship) becomes niche and laughable, thus making those who believe it ever more defensive and entrenched.
That being said why does anyone believe Jamie Dornan and Dakota Fanning are together? Non capisco.