This syntax is already supported by Evan Balster’s Condition plugin—which was part of the problem. The initial proposal for a core if/else defined an <$if> widget with <$then> <$elseif> <$else> widgets nested inside it—but to my understanding, it would not have supported <$else> following a <$list> or <$reveal> (nor would it have supported non-nested <$if></$if><$else></$else> sequences). As @CodaCoder observed, this would have been a breaking change for those of us already using Evan’s plugin, which has been around since 2017.
The new conditional syntax was thus a compromise to protect backwards compatibility. I agree that it’s visually clumsy, but I’m glad to have it, as it means I can happily ignore it and continue using <$else> as I have for years.
I’m not entirely sure I follow here. As (I suppose) a power user, I actually find myself using if-else if-else chains all the time in my templates—most frequently to determine which subtemplate should be used.
Sorry for the digression, @TW_Tones! I’m happy for you to become the local <% if %> expert. 