H & O were relevent for around 10 years, late 70's on, don't know why you would think "last 35 years" is definitive.
In the same time period, The Police, INXS, Phil Collins, John Mellencougar, etc, produced the same number of hit songs, and many would consider them better composer/artist/musicians.
If the syrupy, r&b, pop 40 is your thing, maybe Lionel Richie would also fill the bill for you. I mean competing with groups like "The Knack" and Nick Gilder
for top 40 am radio space was not exactly a great accomplishment back then.
Decent composers in their own right, sure I would agree, but top studio musicians of the day,, no where near it. I'm not telling you you shouldn't like them just like you're not gonna tell me what to like, but I think you're nuts if you believe anyone around here is gonna consider them as "the top group" for anything like a 3+ decade span of time.